Chapter 5- Internet and Web
Introduction:
In today’s world, computers and devices are interconnected through networks, allowing information to be exchanged globally in real time. This chapter provides an overview of computer networks, their types, and essential components, such as network devices and topologies. It also explores the internet and its applications, including websites, web pages, and the technology behind web servers and hosting.
Computer Networks
A computer network is a system where two or more computers or devices are connected to share data and resources.
Examples of networks include social networks, mobile networks, and banking networks.
Types of Networks
Local Area Network (LAN): Covers a small area, such as a room or building, with high data transfer speeds.
Metropolitan Area Network (MAN): Connects multiple LANs across a city, like cable TV networks.
Wide Area Network (WAN): Covers large distances, connecting computers globally; the internet is the largest WAN.
Network Devices
Modem: Converts digital data to analog signals for internet transmission.
Ethernet Card: Connects computers to wired networks, often through an Ethernet cable.
Repeater: Strengthens signals that weaken over long distances.
Hub: Connects multiple devices but broadcasts data to all, leading to possible data collision.
Switch: More efficient than a hub; directs data to the specific device it’s intended for.
Router: Directs data between different networks, often connecting LANs to the internet.
Gateway: Links a network with external networks, like the internet, acting as an entry/exit point.
Networking Topologies
Types of Topologies
Mesh Topology: Each device connects to every other device, ensuring reliability but with high setup costs.
Ring Topology: Devices form a closed loop, sending data in one direction; useful for controlled data flow.
Bus Topology: Devices connect to a central cable or “bus,” but if the bus fails, the entire network can be affected.
Star Topology: Devices connect to a central hub, so if one device fails, others remain unaffected.
Tree Topology: A mix of star and bus topologies, commonly used in wide area networks.
The Internet
The Internet is a global network connecting billions of devices.
It allows for diverse applications like information sharing, social networking, and e-commerce.
Applications of the Internet
World Wide Web (WWW): An interconnected system of web pages accessed via the internet.
Email: Allows users to send messages and files instantly.
Chat: Real-time text communication between users.
Voice Over Internet Protocol (VoIP): Allows voice calls over the internet, often at lower costs than traditional calls.
Web Technologies
Website
A website is a collection of related web pages stored on a web server, often for a specific purpose like information sharing or e-commerce.
Web Page
A web page is a single document within a website, created using HTML and often designed with CSS for styling.
Web Server
A web server stores and delivers web pages to users upon request, responding to browser queries and hosting website files.
Web Hosting
Web hosting is a service that allows individuals or businesses to make their websites accessible online by storing them on a server.
Web Browser and Settings
A web browser is software that allows users to view web pages and interact with websites. Examples include Google Chrome, Mozilla Firefox, and Safari.
Browser Settings: Users can customize settings such as privacy, search engines, and download preferences.
Add-ons and Plug-ins: Tools like Flash Player enhance browser functionality, while add-ons add specific features.
Conclusion:
Networks and the internet have transformed how we communicate, access information, and interact globally. From LANs in homes to the internet connecting continents, networking technology facilitates instant data sharing and collaboration. The tools discussed, from modems to web browsers, support seamless connectivity and access to information worldwide.
Recap:
Computer networks connect devices for data sharing; types include LAN, MAN, and WAN.
Network devices like modems, routers, and switches enable communication within and between networks.
Topologies such as mesh, ring, and star define network structures.
The internet supports applications like the WWW, email, chat, and VoIP.
A web server hosts websites, and web browsers allow users to access and view web content.
