Unit IV: Introduction to Internet and WWW

Course: Fundamentals of Information Technology
Code: CAIDC101

Basics of Computer Networks

A computer network is a system of interconnected computers that share resources and information.

Network Types: LAN, MAN, WAN

Networks are classified based on the geographical area they cover:

• Local Area Network (LAN): Connects devices within a small area like a room, home, or office building.
• Metropolitan Area Network (MAN): Spans a larger area such as a city or a large campus.
• Wide Area Network (WAN): Covers a broad geographical area, such as a country or the entire world.

Network Topology

Network topology refers to the physical or logical arrangement of nodes (computers) and connections in a network.

Common types include:

• Star Topology: All nodes are connected to a central hub.
• Bus Topology: Nodes are connected to a single central cable.
• Ring Topology: Each node is connected to two others, forming a closed loop.
• Mesh Topology: Every node is connected to every other node for high redundancy.

Concept of Internet & WWW

• Internet: A global network of networks connecting millions of computers worldwide.
• WWW (World Wide Web): A system of interlinked hypertext documents accessed via the Internet using a web browser.
• Applications: Communication, research, education, entertainment, and e-commerce.

IP Address, URL, and ISP

• IP Address: A unique numerical label assigned to each device on a network (e.g., 192.168.1.1).
• Website Address and URL: The human-readable address used to locate a resource on the web (e.g., https://www.knowlet.in).
• ISP (Internet Service Provider): A company that provides access to the Internet.
• Internet Protocol: The set of rules governing how data is sent and received over the Internet.

Modes of Connecting to the Internet

There are several ways to connect to the Internet depending on the device and availability:

• Wi-Fi: Wireless networking for local devices.
• Hotspot: Sharing a mobile device's data connection wirelessly.
• Broadband: High-speed data transmission over telephone or cable lines.
• LAN Cable: Direct physical connection via an Ethernet cable.
• USB Tethering: Using a smartphone as a modem for a PC via a USB cable.

Web Surfing and Search Engines

• Surfing the Web: Moving from one page to another using hyperlinks.
• Search Engines: Specialized websites (like Google or Bing) used to find information on the web.
• Web Browsing Tasks: Searching for information, downloading web pages, and printing web pages.