Lecture 4 - Connecting and Communicating Online

Applications of ICT

Presented by Dr. Mir Yasir Umair, Associate Professor, MCS, NUST PAKISTAN.

Connecting and Communicating Online

• Importance of Communication: Communication is essential for daily operations in personal, professional, and societal contexts. It involves the efficient exchange of information from one point to another, which is crucial for decision-making and collaboration.

• Telecommunication (Telecom): This term refers to the exchange of information over long distances through electronic means. It encompasses various forms of communication, including voice calls, video calls, and overall data transfer.

• Computer Networks: These networks enable local data communication among nodes (devices such as computers, smartphones, and printers). Nodes connected in a local network can communicate only among themselves, restricting outsider access for security and efficiency.

• Global Communication: To establish global communication, local networks connect, forming a "network of networks," which allows for seamless interaction across vast distances.

Types of Networks

Local Area Network (LAN)

• A LAN is a network covering a small geographical area such as a home, office, or building. It allows for high-speed connections to devices within close proximity, fostering quick data transfer and shared access to resources.

• Examples: Home Wi-Fi networks, office networks, and school computer labs.

Wide Area Network (WAN)

• A WAN spans large geographic areas like cities and countries, connecting multiple LANs. It utilizes public or private communication infrastructure, including telephone lines, satellites, and fiber-optic cables.

• Examples: The Internet, corporate networks connecting multiple offices across towns and nations.

Metropolitan Area Network (MAN)

• A MAN covers a city or a large campus. It is larger than a LAN but smaller than a WAN, connecting multiple buildings or facilities within a defined area.

• Examples: Citywide Wi-Fi networks, university networks servicing a large campus.

Relation of Networks to the Internet

• The Internet acts as a global WAN that connects multiple LANs, MANs, and WANs, allowing information to flow seamlessly between different types of networks.

• LANs connect to the Internet through routers, which redirect packets of data to and from Internet Service Providers (ISPs), enabling users to access online resources.

• WANs facilitate data transmission across countries and continents, allowing multinational companies to operate and exchange information globally.

Overview of the Internet

• The Internet is a vast collection of interconnected networks which link millions of businesses, government agencies, educational institutions, and individuals. It is not only a medium for communication but also forms the foundation of the digital revolution.

• Information Sharing: The Internet enables instant information sharing across the globe, impacting education, business, and personal communication.

• Today, billions of users access various services online, including but not limited to web browsing, messaging, video communication, and e-commerce platforms.

Internet Connectivity through ISPs

• Internet Service Providers (ISPs) play a crucial role in providing internet connectivity and dedicated servers for hosting services like web servers and email servers.

• The structure of the Internet includes an edge (which consists of host systems such as computers and smartphones) and a core (composed of a network of routers and switching devices).

History of the Internet

• The Internet's origins date back to 1969 as ARPANET, a project funded by the US Department of Defense to connect research and academic institutions. It initially connected four main computers at different US universities and rapidly evolved to over 1,000 individual hosts by 1984.

• The World Wide Web was introduced in 1991, providing an easy-to-use interface for accessing, sharing, and managing vast amounts of online resources.

Ownership of the Internet

• No single entity owns the Internet; instead, various organizations maintain different parts of it. The World Wide Web Consortium (W3C) oversees research and provides standards and guidelines for web technologies.

• Over 400 organizations contribute to the evolution and management of the Internet, ensuring its accessibility and innovation.

The Evolution of the Web

• The web has witnessed four key generations:

  • Web 1.0: Characterized by static web pages, primarily featuring search engines connecting users to information.

  • Web 2.0: Marked by the rise of social media, allowing users to create, share, and interact with content, thus connecting friends and family more effectively.

  • Web 3.0: Known as the semantic web, it allows for data relationships to be identified, enabling smarter web applications that understand context and meaning.

  • Web 4.0: Describes the mobile web era, focusing on leveraging mobile tools and applications for improved data accessibility and interactivity, promoting a more dynamic user experience.

Distinction Between the Internet and the Web

• It is important to understand the distinction between the Internet and the Web. The Internet is a physical network composed of cables, satellites, and protocols. In contrast, the Web serves as a multimedia interface that provides users with access to a myriad of internet resources, such as websites and applications.

• Browsers: Specific software programs, such as Google Chrome, Mozilla Firefox, and Microsoft Edge, allow users to access and interact with web content, making the browsing experience user-friendly and efficient.

URL and DNS

• URLs: Universal Resource Locators (URLs) are the web addresses that are essential for browsers to locate and access resources on the Web.

• Domain Name System (DNS): The DNS functions by translating user-friendly domain names (e.g., google.com) into numerical IP addresses, enabling efficient routing of requests across the network.

Types of Websites

• The internet hosts a variety of websites serving different purposes, including:

  • Search engines (e.g., Google)

  • Social networks (e.g., Facebook)

  • Informational sites (e.g., Wikipedia)

  • Media sharing platforms (e.g., YouTube)

Web Technologies

• Various web technologies enhance user experience and website functionality, including:

  • HTML: A markup language used for creating and displaying web pages' structural content.

  • JavaScript: A programming language that allows for dynamic content and interactivity within web pages.

  • PHP: A server-side scripting language that enables the creation of dynamic web pages, adding interactivity and user engagement.

  • CSS: Cascading Style Sheets control the visual styles of web pages, allowing for customized presentation of content.

File Transfer Utilities

• File transfer utilities are essential for uploading and downloading files online, ensuring data sharing and management. These utilities include:

  • Web-based services (e.g., Google Drive)

  • Peer-to-peer technologies like BitTorrent

  • FTP/SFTP for transferring larger files between clients and servers.

Modes of Internet Service

• Internet connectivity is achieved through various service modes, including:

  • DSL: High-speed connectivity using existing telephone lines.

  • Cable: High-speed access using coaxial cable, usually offered by television providers.

  • Fiber-Optic: Represents the fastest available speeds using light signals transmitted through glass fibers.

  • Satellite: Ideal for users in remote areas where traditional services might not reach, utilizing satellite communications for internet access.

Key Points on Internet Service Providers (ISPs)

• ISPs enable users to access the internet by charging a subscription fee for their service. Common ISPs include AT&T, Comcast, PTCL, and Nayatel, offering a range of service options tailored to consumer needs.

How a Home User Requests a Webpage

• The process of how a home user requests a webpage involves several steps:

  1. A digital request is sent from a device (such as a computer or smartphone) to a cable modem.

  2. The request travels through the cable system and is routed through high-speed fiber-optic lines.

  3. The ISP routes the request to the server that hosts the webpage, allowing the response and content to be delivered back to the user's device.

Browsers and Their Functions

• Browsers provide users access to the internet and its vast array of web resources. Commonly used browsers include Google Chrome, Mozilla Firefox, and Microsoft Edge. They interpret HTML documents, manage user settings and bookmarks, and facilitate user interaction with web applications.

Conclusion

• This presentation, led by Dr. Mir Yasir Umair, highlights crucial aspects of ICT applications, emphasizing the importance of connectivity, the structure, and the functioning of networks and the internet. Questions are welcomed to encourage further engagement and clarification.