Top 10 Computer Courses in High Demand

Certainly! Here are ten computer courses that are currently in high demand, reflecting industry trends and technological advancements:

1) Web Designing

Web design is the method of creating and managing a website's appearance to improve user experience and meet organizational objectives. It makes sure websites are both aesthetically pleasing and easy to use by including interactive elements, color palettes, typography, and layout design.

Among the career options are:

• Web designer: Creates the look and feel of websites.
• UI/UX Designer: specializes in experience and user interface design.
• Front-end developer: Uses HTML, CSS, and JavaScript to transform designs into useful web pages.
• Web design consultant: Offers professional guidance on tactics and advancements in web design.

2) Data Science

Data science is the application of statistical analysis, machine learning, and data visualization to extract knowledge and insights from data. To understand complicated datasets and inform decisions, it integrates domain knowledge, mathematics, and programming.

Among the career options are:

• A data scientist examines data to help in strategic decision-making.
• Data analysts produce reports by interpreting data.
• Algorithms and models are developed by machine learning engineers.
• Creates and manages data pipelines as a data engineer.
• A business intelligence analyst uses data visualization to deliver insights that can be put to use.
• Data consultants offer guidance on the deployment and strategy of data.

3) Multimedia & Animation

In order to captivate viewers, multimedia and animation creates dynamic visual material by fusing text, graphics, video, and animation. The integration of technical expertise and artistic imagination yields interactive and visually captivating media.

Among the career options are:

• Animators make animated sequences and characters for movies, television shows, or video games.
• Designers of visual elements for digital media, advertising, and entertainment are known as multimedia artists.
• Video editors compile and edit footage for a variety of mediums.
• 3D modelers build three-dimensional characters for movies, video games, or computer programs.

4) Internet of Things (IoT) 

An online network of interconnected items that exchange data and communicate is referred to as the "Internet of Things" (IoT). It has every piece of hardware—sensors, software, and other—necessary to build intelligent appliances and systems for everything from home automation to commercial automation.

Among the career options are: 

• IoT Developer: Develops and implements IoT solutions and apps.
• Hardware and firmware for IoT devices are created by embedded systems engineers.
• Data analysts examine the data generated by Internet of Things devices for patterns.
• IoT Solutions Architect: Creates and integrates Internet of Things solutions for businesses.

5) Cybersecurity 

Cybersecurity is the defense against online threats and illegal access to computer networks, systems, and data. It includes procedures and tools made to protect private data and guarantee the availability, integrity, and confidentiality of digital assets.

Among the career options are:

• Cybersecurity Analyst: Keeps an eye on security events and takes appropriate action.
• An ethical hacker uses attack simulations to test and assess security measures.
• Security engineers create and put into place infrastructure and security solutions.
• An incident responder controls and lessens the effects of security lapses.
• Security consultant: Offers guidance to companies on compliance and best practices in security.

6) Big Data Analytics 

Analyzing massive and intricate information for patterns, trends, and insights that inform strategic choices is known as big data analytics. It processes and analyzes enormous volumes of data beyond the capability of conventional data processing by using sophisticated analytical techniques and tools.

 Among the career options are:

• A data scientist examines huge databases to glean insightful information.
• A big data engineer creates and manages information processing infrastructure.
• Analyzes data to make informed business decisions.
• Reports and visualizations are produced by business intelligence analysts to aid in decision-making.
• A data architect creates data structures and frameworks for efficient access and storage.

7) Digital marketing

Digital marketing is the practice of advertising goods and services via online platforms like websites, email, social media, and search engines. In order to engage consumers and spur corporate growth, it includes techniques like SEO, content marketing, PPC, and social media marketing.

 Among the career options are:

• Manager of Digital Marketing: In charge of campaigns and strategy for digital marketing.
• SEO Specialist: Improves content on websites to rank higher in search results.
• A content marketer produces and oversees material to draw in and keep viewers interested.
• PPC Specialist: Campaign manager for pay-per-click advertising.
• Creates and implements social media strategy as a social media manager.

8) Software Development 

The process of creating, coding, testing, and maintaining software systems or applications is known as software development. It entails utilizing development tools and programming languages to produce software that satisfies user requirements and addresses certain issues.

 Among the career options are:

• Software developers create and design software programs.
• Software engineers use engineering concepts to design software.
• Web developers build and manage websites and online programs.
• App developer for mobile devices: Creates apps for mobile platforms.
• Software distribution and maintenance are streamlined by DevOps engineers, who integrate development and operations.

9) Mobile App Development 

Mobile app development is the process of creating software specifically for portable electronic devices, such tablets and smartphones. It include designing, developing, testing, and releasing software for platforms such as iOS and Android.

Among the career options are:

• Works as a mobile app developer, developing and overseeing iOS and Android applications.
• iOS Developer: Concentrates on creating apps for Apple devices using Swift or Objective C.
• Android Developer: Develops apps for Android handsets using Java or Kotlin.
• Works as a mobile UI/UX designer to create user interfaces and experiences for mobile applications.
• App quality assurance (QA) testers test the usability and functionality of mobile apps.

10) Graphic Designing

Graphic Designing  involves creating visual content to communicate messages effectively through various mediums like print, digital, and social media. It includes designing layouts, logos, posters, and other visual elements using tools like Adobe Photoshop, Illustrator, and InDesign.

Among the career options are:

• Graphic Designer: Designs visual content for brands and media.
• Art Director: Oversees visual projects and design teams.
• Web Designer: Creates visually appealing websites.
• Brand Designer: Develops brand identities and marketing materials.
• UX/UI Designer: Focuses on user experience and interface design for digital products.

What is Digital Marketing

Digital marketing is a broad and dynamic field that encompasses a wide range of online marketing activities and strategies. It aims to connect businesses and target audiences through digital channels. In today's growing digital world where internet and electronic devices play an important role in our daily lives, digital marketing has become essential businesses of all sizes can effectively reach and engage with their customers.

Development and importance of digital marketing

Digital marketing has grown rapidly over the past few decades along with technological advancements and changes in consumer behavior. Traditionally, marketing efforts focused primarily on print media, television, radio, and other non-online channels. But the rise of the Internet and proliferation of digital devices like smartphones and tablets are changing the way businesses and consumers interact.

The primary importance of digital marketing is the ability to reach global audiences quickly and cost-effectively. Unlike traditional marketing channels, which often have geographic and budgetary constraints, digital marketing enables businesses to target specific demographics, track the performance of their campaigns in real-time, and adapt their strategies accordingly.

Fundamentals of Digital Marketing

Digital marketing involves a variety of strategies and tactics, each of which serves a specific purpose in reaching and engaging audiences. Some of the key elements of digital marketing are:

1. Search Engine Optimization (SEO): SEO focuses on optimizing websites to increase visibility and improve rankings in search engine results pages SERPs). Using logic and practicality over search algorithms, businesses search on Google, Bing and Yahoo! You can attract organic (unpaid) traffic from various engines.

2. Pay-Per-Click (PPC) Advertising: PPC advertising places an ad on a search engine or other website and pays a fee every time someone clicks on the ad. Platforms like Google Ads and social media platforms like Facebook Ads allow businesses to drive targeted traffic to their websites by targeting specific keywords, demographics, and interests.

3. Social Media Marketing: Social media platforms like Facebook, Instagram, Twitter, LinkedIn, and Tiktok are powerful ways to build brand awareness, connect with audiences, and increase traffic and sales. Social media marketing includes creating and sharing content, interacting with fans, placing paid advertisements, and analyzing engagement metrics to optimize campaigns.

4. Content Marketing: Content marketing focuses on creating and sharing valuable, relevant, and consistent content to attract and retain a clearly defined audience. Content can take a variety of forms, including blog posts, articles, videos, infographics, podcasts, and e-books. High-quality content not only educates and entertains but also helps establish a brand's authority and credibility in its operations.

5. Email Marketing: Email marketing involves sending targeted messages to customers or customer lists to promote products, services or special offers. Effective email marketing campaigns are designed to personalize, segment, drive leads, build relationships, and increase conversions.

6. Digital Advertising: In addition to PPC and social media advertising, digital advertising includes online advertising, including display ads, live ads, video ads, and other forms of marketing (targeting users who have previously visited your Have interacted with the brand online).

7. Influencer Marketing: Influencer marketing involves partnering with influencers on social media platforms to promote products or services to their followers. Influencers often have dedicated and engaged audiences, making them effective advocates for brands looking to expand their reach and credibility.

8. Mobile Marketing: With the increasing use of smartphones and tablets, mobile marketing focuses on reaching audiences on their mobile devices through mobile-optimized websites, mobile apps, SMS (text) marketing, and location-based marketing strategies. Is concentrated.

Benefits of Digital Marketing

Digital marketing offers many benefits over traditional marketing channels, such as

Global Reach: Digital marketing enables businesses to instantly reach global audiences through a variety of online channels, breaking geographical barriers.

Targeted Advertising: Digital marketing enables precise targeting based on demographics, interests, behavior and other factors, ensuring that marketing messages reach the most relevant audiences.

Cost-Effectiveness: Compared to traditional advertising methods such as print and TV advertising, digital marketing usually requires less initial investment and can be cost-effective, especially for small businesses and start-ups. 

Measurable Results: Digital marketing provides robust analytics and data-driven insights, and allows businesses to track and measure the performance of their campaigns in real-time. Metrics such as website traffic, conversion rates, engagement levels and ROI (return on investment) can be monitored and analyzed to create better marketing strategies.

Increased Customer Engagement: Digital marketing encourages two-way communication between businesses and their customers through social media interactions, email newsletters, comments, reviews, etc. This connection helps build strong customer relationships and long-term loyalty.

Flexibility and Adaptability: Digital marketing campaigns can be adapted quickly and efficiently based on real-time data and insights. This flexibility enables companies to respond more quickly to market trends, customer preferences, and competitive pressures.

Challenges in Digital Marketing

While digital marketing offers some benefits, it also poses challenges for businesses:

Digital Noise: With digital channels broadcasting content, it can be difficult to stand out from the competition and capture audience attention.

Data Privacy and Security: Growing data privacy and regulatory concerns (such as GDPR in Europe and CCPA in California) require businesses to handle customer data responsibly and transparently.

Continuous Evolution: Digital marketing trends, algorithms and techniques are constantly evolving. Staying abreast of new trends and adapting to changes in digital platforms and consumer behavior is essential to stay on track.

Competition: The reach of digital marketing means that businesses of all sizes, from startups to multinationals, can compete online for the same audience, requiring distinct and innovative strategic differentiation.

Future Trends in Digital Marketing

Looking ahead, several trends are shaping the future of digital marketing:

Artificial Intelligence (AI) and Machine Learning: Digital marketing is increasingly using AI-powered tools and algorithms for data analysis, personalized recommendations, chatbots, content creation, and predictive analytics.

Voice Search Optimization: As voice-activated devices like smart speakers and virtual assistants (e.g., Siri, Alexa) gain popularity, content optimization for voice search queries is becoming increasingly important.

Video Marketing: Video content continues to dominate online consumption. Platforms like YouTube, TikTok and Instagram Stories are increasing the demand for engaging and interactive video content.

Personalization: Consumers expect personalized experiences and interactions from brands. Using data to deliver targeted content, recommendations and offers will be essential to increasing engagement and conversions.

Augmented Reality (AR) and Virtual Reality (VR): AR and VR technologies are being integrated into digital marketing channels to enhance customer experience, product demonstrations, and interactive presentations.

In conclusion, digital marketing is a multi-faceted discipline with various strategies and tactics aimed at reaching and engaging the target audience through digital channels From SEO and From PPC advertising to social media marketing, content marketing, email marketing, and beyond By embracing digital marketing strategies and technological advancements and technological learning, businesses can navigate the digital landscape effectively, driving growth and achieve their marketing objectives in the digital age.

What is HTML?

HTML, which stands for Hypertext Markup Language, is the language used to create and design web pages. It provides a structured way of organizing and displaying content on the World Wide Web. HTML is the foundation of web development. It describes the layout and structure of a web document through the organization of tags and attributes. These tags are enclosed in corner brackets `< >` and provide guidance to web browsers on how to display the content.

The basic structure of an HTML document

Every HTML document follows a basic format:

<!DOCTYPE html>: This declaration specifies the HTML version in use (in this case HTML5).

<html>: The root of the HTML page.

<head>: Contains meta-information about the document, such as title and links to style sheets.

<title>: Define the title of the document (displayed in the browser's title bar or tab).

<body>: contains the main body of the document, such as text, images, links, and so on.

HTML tags and elements

HTML tags are used to describe the different elements of a web page. Some common tags are:

<h1> to <h6>: Title with different position.

<p>: Paragraphs in text.

<a>: Anchor tags to create links.

<img>: Inserts images.

<ul>, <ol>, <li>: Define an unsorted list, a sorted list, and a list item.

<table>, <tr>, <td>: Used to create tables with their rows and cells.

<form>, <input>, <button>: objects for creating input text and buttons and other form controls.

Attributes

HTML elements can have attributes that provide additional information about them. Attributes appear in the opening tag and are usually name-value pairs.

For example:

href, src, alt, id, name, type are some of the common attributes used in object types.

Semantic HTML

Semantic HTML is the use of HTML tags that define the meaning of the content. This helps search engines and screen readers better understand website layout, improves navigation and SEO.

For example:

HTML5 features

HTML5 introduced many new features and innovations to improve web development:

<video> and <audio>: Media files will be loaded directly into web browsers.

<canvas>: Draws graphics and animations using JavaScript.

<svg>: An editable vector graphic for creating vector graphics and animations.

<article> and <section>: structure elements for organizing content.

<header>, <footer>, <nav>, <aside>: semantic elements used to describe specific parts of a web page.

HTML and CSS

When HTML describes the structure and content of a web page, CSS (Cascading Style Sheets) is used to create and organize that information. CSS controls all aspects like colors, fonts, spacing, and layout.

Examples of linking CSS to HTML:

HTML and JavaScript

JavaScript is used to add dynamic interactions and actions to web pages. It can process the HTML content, respond to user actions, and communicate with servers.

Examples of linking JavaScript and HTML:

HTML best practice

HTML valid: Use valid and optimized HTML to ensure browser compatibility.

Semantic Markup: Use appropriate tags to clearly define structure and meaning.

Separation of nuisances: Keep HTML for layout, CSS for presentation, and JavaScript for actions.

Accessibility: Make sure your web pages are accessible to all users, including those with disabilities.

SEO: Use semantic markup and relevant keywords to improve search engine rankings.

Conclusion

HTML is the primary language for building web pages, providing structure and information that users interact with. It is constantly evolving with new standards and features, supporting richer and more interactive web experiences. Understanding HTML is essential for everyone involved in web development, from beginners creating simple pages to professionals developing complex web applications.

What is Operating System

Operating System:-

Computer - Operating System:-

• The Operating System is a program with the following features −

• An operating system is a program that acts as an interface between the software and the computer hardware. 

• It is an integrated set of specialized programs used to manage overall resources and operations of the computer. 

• It is a specialized software that controls and monitors the execution of all other programs that reside in the computer, including application programs and other system software.

• As the name suggests, an operating system is a type of software without which you cannot operate or run a computer. It acts as an intermediary or translation system between computer hardware and application programs installed on the computer. In other words, you cannot directly use computer programs with computer hardware without having a medium to establish a connection between them.

• Besides this, it is also an intermediary between the computer user and the computer hardware as it provides a standard user interface that you see on your computer screen after you switch on your computer. For example, the Windows and the Mac OS are also operating systems that provide a graphical interface with icons and pictures to enable users to access multiple files and applications simultaneously.

• So, although the operating system is itself a program or software, it allows users to run other programs or applications on the system. We can say that is works behind the scenes to run your computer.

 

Objectives of Operating System:-

• The objectives of the operating system are −

• To make the computer system convenient to use in an efficient manner. 

• To hide the details of the hardware resources from the users. 

• To act as an intermediary between the hardware and its users, making it easier for the users to access and use other resources. 

• To provide users a convenient interface to use the computer system. 

• To keep track of who is using which resource, granting resource requests, and mediating conflicting requests from different programs and users.

• To manage the resources of a computer system. 

• To provide efficient and fair sharing of resources among users and programs. 

Characteristics of Operating System:-

• Memory Management: Keeps track of the primary memory, i.e. what part of it is in use by whom, what part is not in use, etc. and allocates the memory when a process or program requests it.

• Processor Management: Allocates the processor (CPU) to a process and deallocates the processor when it is no longer required.

• Device Management: Keeps track of all the devices. This is also called I/O controller that decides which process gets the device, when, and for how much time.

• File Management: Allocates and de-allocates the resources and decides who gets the resources.

• Security: Prevents unauthorized access to programs and data by means of passwords and other similar techniques. 

• Job Accounting: Keeps track of time and resources used by various jobs and/or users.

• Control Over System Performance: Records delays between the request for a service and from the system. 

What Is Topology? Advantages And Disadvantages Of Topologies And How Many Types Of Topology

What is Topology?

• Topology defines the structure of the network of how all the components are interconnected to each other. There are two types of topology: physical and logical topology. 

Types of Network Topology

• Bus Topology
• Ring Topology
• Tree Topology
• Star Topology
• Mesh Topology
• Hybrid Topology

Bus Topology

• The bus topology is designed in such a way that all the stations are connected through a single cable known as a backbone cable. 
• Each node is either connected to the backbone cable by drop cable or directly connected to the backbone cable.
• When a node wants to send a message over the network, it puts a message over the network. All the stations available in the network will receive the message whether it has been addressed or not. 

Advantages of Bus Topology

• Low-cost cable: In bus topology, nodes are directly connected to the cable without passing through a hub. Therefore, the initial cost of installation is low.

Disadvantages of Bus Topology

• Extensive cabling: A bus topology is quite simpler, but still it requires a lot of cabling. 

Ring Topology

• Ring topology is like a bus topology, but with connected ends.
• The node that receives the message from the previous computer will retransmit to the next node.
• The data flows in one direction, i.e., it is unidirectional.
• The data flows in a single loop continuously known as an endless loop.
• It has no terminated ends, i.e., each node is connected to other node and having no termination point. The data in a ring topology flow in a clockwise direction. 

Advantages of Ring Topology

• Network management: Faulty devices can be removed from the network without bringing the network down. 
• Product availability: Many hardware and software tools for network operation and monitoring are available. 

Disadvantages of Ring Topology

• Difficult troubleshooting: It requires specialized test equipment to determine the cable faults. If any fault occurs in the cable, then it would disrupt the communication for all the nodes.
• Failure: The breakdown in one station leads to the failure of the overall network. 

Star Topology

• Star topology is an arrangement of the network in which every node is connected to the central hub, switch or a central computer.
• The central computer is known as a server, and the peripheral devices attached to the server are known as clients. 

Advantages of Star Topology

• Network control: Complex network control features can be easily implemented in the star topology. Any changes made in the star topology are automatically accommodated.
• Limited failure: As each station is connected to the central hub with its own cable, therefore failure in one cable will not affect the entire network.

Disadvantages of Star Topology

• A Central point of failure: If the central hub or switch goes down, then all the connected nodes will not be able to communicate with each other.
• Cable: Sometimes cable routing becomes difficult when a significant amount of routing is required. 

Tree Topology

• Tree topology combines the characteristics of bus topology and star topology.
• A tree topology is a type of structure in which all the computers are connected with each other in hierarchical fashion.
• The top-most node in tree topology is known as a root node, and all other nodes are the descendants of the root node.
• There is only one path exists between two nodes for the data transmission. Thus, it forms a parent-child hierarchy. 

Advantages of Tree Topology

• Easily expandable: We can add the new device to the existing network. Therefore, we can say that tree topology is easily expandable.

Disadvantages of Tree Topology

• High cost: Devices required for broadband transmission are very costly.
• Failure: A tree topology mainly relies on main bus cable and failure in main bus cable will damage the overall network. 

Mesh Topology

• Mesh technology is an arrangement of the network in which computers are interconnected with each other through various redundant connections.
• There are multiple paths from one computer to another computer.
• It does not contain the switch, hub or any central computer which acts as a central point of communication.
• The Internet is an example of the mesh topology.
• Mesh topology is mainly used for WAN implementations where communication failures are a critical concern. 

Advantages of Mesh Topology

• Reliable: The mesh topology networks are very reliable as if any link breakdown will not affect the communication between connected computers.
• Fast Communication: Communication is very fast between the nodes.

Disadvantages of Mesh Topology

Cost: A mesh topology contains a large number of connected devices such as a router and more transmission media than other topologies.

Management: Mesh topology networks are very large and very difficult to maintain and manage. If the network is not monitored carefully, then the communication link failure goes undetected. 

Hybrid Topology

• The combination of various different topologies is known as Hybrid topology.
• A Hybrid topology is a connection between different links and nodes to transfer the data.
• When two or more different topologies are combined together is termed as Hybrid topology and if similar topologies are connected with each other will not result in Hybrid topology. For example, if there exist a ring topology in one branch of ICICI bank and bus topology in another branch of ICICI bank, connecting these two topologies will result in Hybrid topology. 

Advantages of Hybrid Topology

• Reliable: If a fault occurs in any part of the network will not affect the functioning of the rest of the network.
• Scalable: Size of the network can be easily expanded by adding new devices without affecting the functionality of the existing network.

Disadvantages of Hybrid Topology

Complex design: The major drawback of the Hybrid topology is the design of the Hybrid network. It is very difficult to design the architecture of the Hybrid network.

Costly Hub: The Hubs used in the Hybrid topology are very expensive as these hubs are different from usual Hubs used in other topologies. 

SMTP, POP, POP3, IMAP, MIME

Simple Mail Transfer Protocol (SMTP):-

• Email is emerging as one of the most valuable services on the internet today. Most of the internet systems use SMTP as a method to transfer mail from one user to another. SMTP is a push protocol and is used to send the mail whereas POP (post office protocol) or IMAP (internet message access protocol) are used to retrieve those mails at the receiver’s side.  

(SMTP):-

• SMTP is an application layer protocol. The client who wants to send the mail opens a TCP connection to the SMTP server and then sends the mail across the connection. The SMTP server is always on listening mode. As soon as it listens for a TCP connection from any client, the SMTP process initiates a connection on that port (25). After successfully establishing the TCP connection the client process sends the mail instantly. 

SMTP Protocol:-

The SMTP model is of two type:

1. End-to-end method
2. Store-and-forward method

Model Of SMTP System:-

• In the SMTP model user deals with the user agent (UA) for example Microsoft Outlook, Netscape, Mozilla, etc. In order to exchange the mail using TCP, MTA is used. The users sending the mail do not have to deal with the MTA it is the responsibility of the system admin to set up the local MTA. The MTA maintains a small queue of mails so that it can schedule repeat delivery of mail in case the receiver is not available. The MTA delivers the mail to the mailboxes and the information can later be downloaded by the user agents. 

Both the SMTP-client and MSTP-server should have 2 components:-

1. User agent (UA)
2. Local MTA

Post Office Protocol (POP):-

• Post Office Protocol (POP) is a type of computer networking and Internet standard protocol that extracts and retrieves email from a remote mail server for access by the host machine. 

• POP is an application layer protocol in the OSI model that provides end users the ability to fetch and receive email. 

• Post Office Protocol is the primary protocol behind email communication. POP works through a supporting email software client that integrates POP for connecting to the remote email server and downloading email messages to the recipient’s computer machine. 

• POP3 stands for Post Office Protocol Version3 (Current Version). POP is a protocol which listens on port 110 and is responsible for accessing the mail service on a client machine. POP3 works in two modes such as Delete Mode and Keep Mode. 

1. Delete Mode: A mail is deleted from the mailbox after successful retrieval. 
2. Keep Mode: The Mail remains Intact in the mailbox after successful retrieval. 

Difference between SMTP and POP3:-

• For sending and receiving messages, we use two protocols one is SMTP (Simple Mail Transfer Protocol) and another is POP3 (Post Office Protocol version 3). They are also called as PUSH and POP protocols respectively. They are agents, Message Transfer Agent and Message Access Agent respectively to send and retrieve the messages. 

SMTP:-

1. The port number of SMTP is 25.
2. It is a MTA (Message Transfer Agent) for sending the to the receiver. 

POP3:-

1. The port number of POP3 is 110.
2. It is MAA (Message Access Agent) for accessing the messages from mail box. 
3. It has also two MAAs one is client MAA (Message Access Agent) and another is server is server (Message Access Agent). MAA
4. POP3 is also known as POP protocol. 

IMAP (Internet Message Access Protocol):-

• IMAP (Internet Message Access Protocol) is a standard email protocol that stores email messages on a mail server, but allows the end user to view and manipulate the messages as though they were stored locally on the end user's computing device(s). This allows users to organize messages into folders, have multiple client applications know which messages have been read, flag messages for urgency or follow-up and save draft messages on the server. 

• IMAP can be contrasted with another client/server email protocol, Post Office Protocol 3 (POP3). With POP3, mail is saved for the end user in a single mailbox on the server and moved to the end user's device when the mail client opens. While POP3 can be thought of as a "store-and-forward" service, IMAP can be thought of as a remote file server. 

Multipurpose Internet Mail Extension (MIME) Protocol:-

• Why do we need MIME?

       Limitations of Simple Mail Transfer Protocol (SMTP):

• SMTP has a very simple structure 
• It’s simplicity however comes with a price as it only send messages in NVT 7-bit ASCII format. 
• It cannot be used for languages that do not support 7-bit ASCII format such as- French, German, Russian, Chinese and Japanese, etc.so it cannot be transmitted using SMTP. So, in order to make SMTP more broad we use MIME. 
• It cannot be used to send binary files or video or audio data. 

Purpose and Functionality of MIME:-

• Growing demand for Email Message as people also want to express in terms of Multimedia. So, MIME another email application is introduced as it is not restricted to textual data. 

• MIME transforms non-ASCII data at sender side to NVT 7-bit data and delivers it to the client SMTP. The message at receiver side is transferred back to the original data. As well as we can send video and audio data using MIME as it transfers them also in 7-bit ASCII data. 

Features of MIME:-

• It is able to send multiple attachments with a single message. 
• Unlimited message length. 
• Binary attachments (executables, images, audio, or video files) which may be divided if needed. 
• MIME provided support for varying content types and multi-part messages. 

TCP/IP Model

The OSI Model we just looked at is just a reference/logical model. It was designed to describe the functions of the communication system by dividing the communication procedure into smaller and simpler components. But when we talk about the TCP/IP model, it was designed and developed by Department of Defense (DoD) in 1960s and is based on standard protocols. It stands for Transmission Control Protocol/Internet Protocol. The TCP/IP model is a concise version of the OSI model. It contains four layers, unlike seven layers in the OSI model. The layers are:

1) Process/Application Layer 

2) Host-to-Host/Transport Layer 

3) Internet Layer 

4) Network Access/Link Layer 

TCP/IP Model

• Application Layer
  
• Transport Layer
• Internet Layer
• Network Access Layer

OSI Model

• Application Layer
• Presentation Layer
• Session Layer
• Transport Layer
• Network Layer
• Data Link Layer
• Physical Layer

TCP/IP

1. TCP refers to Transmission Control Protocol.
2. TCP/IP has 4 layers.
3. TCP/IP is more reliable
4. TCP/IP does not have very strict boundaries.
5. TCP/IP follow a horizontal approach.

OSI

1. OSI refers to Open Systems Interconnection.
2. OSI has 7 layers.
3. OSI is less reliable
4. OSI has strict boundaries
5. OSI follows a vertical approach.
6. OSI uses different session and presentation layers. 
7. OSI developed model then protocol. 

1) Network Access Layer 

• This layer corresponds to the combination of Data Link Layer and Physical Layer of the OSI model. It looks out for hardware addressing and the protocols present in this layer allows for the physical transmission of data. We just talked about ARP being a protocol of Internet layer, but there is a conflict about declaring it as a protocol of Internet Layer or Network access layer. It is described as residing in layer 3, being encapsulated by layer 2 protocols.

2) Internet Layer 

• This layer parallels the functions of OSI’s Network layer. It defines the protocols which are responsible for logical transmission of data over the entire network. The main protocols residing at this layer are : 

• IP – stands for Internet Protocol and it is responsible for delivering packets from the source host to the destination host by looking at the IP addresses in the packet headers. IP has 2 versions: IPv4 and IPv6. IPv4 is the one that most of the websites are using currently. But IPv6 is growing as the number of IPv4 addresses are limited in number when compared to the number of users.

3) Transport Layer 

• Transport layer provides services to application layer and takes services from network layer. The data in the transport layer is referred to as Segments. It is responsible for the End to End delivery of the complete message. Transport layer also provides the acknowledgment of the successful data transmission and re-transmits the data if an error is found. 

4) Application Layer 

• At the very top of the OSI Reference Model stack of layers, we find Application layer which is implemented by the network applications. These applications produce the data, which has to be transferred over the network. This layer also serves as a window for the application services to access the network and for displaying the received information to the user.

Client and Server Model

• A client and server networking model is a model in which computers such as servers provide the network services to the other computers such as clients to perform a user based tasks. This model is known as client-server networking model. 
• The application programs using the client-server model should follow the given below strategies:  

Client

• A client is a program that runs on the local machine requesting service from the server. A client program is a finite program means that the service started by the user and terminates when the service is completed. 

Server

• A server is a program that runs on the remote machine providing services to the clients. When the client requests for a service, then the server opens the door for the incoming requests, but it never initiates the service.
• A server program is an infinite program means that when it starts, it runs infinitely unless the problem arises. The server waits for the incoming requests from the clients. When the request arrives at the server, then it responds to the request.

Domain Name System (DNS)

• DNS stands for Domain Name System.  
• DNS is a directory service that provides a mapping between the name of a host on the network and its numerical address. 
• DNS is required for the functioning of the internet. 
• Each node in a tree has a domain name, and a full domain name is a sequence of symbols specified by dots. 
• DNS is a service that translates the domain name into IP addresses. This allows the users of networks to utilize user-friendly names when looking for other hosts instead of remembering the IP addresses.
• DNS is a TCP/IP protocol used on different platforms. The domain name space is divided into three different sections: generic domains, country domains, and inverse domain.  

Label                               Description                            

aero               Airlines and aerospace companies 

biz                  Businesses or firms 

com                Commercial Organizations 

coop               Cooperative business Organizations 

edu                 Educational institutions 

gov                 Government institutions     

info                Information service providers 

int                  International Organizations 

mil                 Military groups 

museum       Museum & other nonprofit organizations 

name             Personal names 

net                 Network Support centers 

org                 Nonprofit Organizations 

pro                 Professional individual Organizations 

Working Of DNS

• DNS is a client/server network communication protocol. DNS clients send requests to the. server while DNS servers send responses to the client. 
• Client requests contain a name which is converted into an IP address known as a forward DNS lookups while requests containing an IP address which is converted into a name known as reverse DNS lookups. 
• DNS implements a distributed database to store the name of all the hosts available on the internet. 

Filer Protocol (FTP)

• FTP stands for File transfer protocol. 
• FTP is a standard internet protocol provided by TCP/IP used for transmitting the files from one host to another. 
• It is mainly used for transferring the web page files from their creator to the computer that acts as a server for other computers on the internet. 
• It is also used for downloading the files to computer from other servers. 

• FTP client is a program that implements a file transfer protocol which allows you to transfer files between two hosts on the internet. 
• It allows a user to connect to a remote host and upload or download the files. 
• It has a set of commands that we can use to connect to a host, transfer the files between you and your host and close the connection. 
• The FTP program is also available as a built-in component in a Web browser. This GUI based FTP client makes the file transfer very easy and also does not require to remember the FTP commands. 

Telnet

• The main task of the internet is to provide services to users. For example, users want to run different application programs at the remote site and transfers a result to the local site. This requires a client-server program such as FTP, SMTP. But this would not allow us to create a specific program for each demand. 
• The better solution is to provide a general client-server program that lets the user access any application program on a remote computer. Therefore, a program that allows a user to log on to a remote computer. A popular client-server program Telnet is used to meet such demands. Telnet is an abbreviation for Terminal Network. 
• Telnet provides a connection to the remote computer in such a way that a local terminal appears to be at the remote side.