Computer networking CBSE Class 9 and 10

Computer networking refers to the practice of connecting computers and other devices to share resources, communicate, and exchange data. Networks can be as small as a local area network (LAN) in a home or office or as large as the global Internet. Networking enables devices to work together efficiently and is the backbone of modern communication.

Types of Computer Networks:

1. Local Area Network (LAN):

   • A LAN connects devices within a limited geographical area, like a home, school, or office. It allows for the sharing of files, printers, and other resources.
   • Example: A Wi-Fi network in a house.

2. Wide Area Network (WAN):

   • A WAN covers a larger geographical area, such as a city, country, or even globally. The Internet is the largest example of a WAN.
   • Example: The network connecting branches of a multinational company.

3. Metropolitan Area Network (MAN):

   • A MAN covers a city or a large campus. It’s larger than a LAN but smaller than a WAN.
   • Example: A city’s public Wi-Fi network.

4. Personal Area Network (PAN):

   • A PAN is used for communication among devices within the range of an individual, such as a smartphone, laptop, or smartwatch.
   • Example: Bluetooth connections between a phone and wireless earbuds.

5. Virtual Private Network (VPN):

   • A VPN allows users to create a secure connection over a public network, such as the Internet, by encrypting data and providing privacy.
   • Example: Using a VPN to securely connect to a company’s internal network from a remote location.

Components of a Computer Network:

1. Nodes (Devices):

   • These are the computers, smartphones, servers, and other devices that are part of the network.

2. Network Interface Cards (NIC):

   • A hardware component that enables a device to connect to the network.

3. Switches:

   • Devices that connect multiple devices on a LAN and direct data between them.

4. Routers:

   • Routers connect different networks, such as a home network to the Internet, and direct data between them.

5. Cables and Wireless Media:

   • Data is transmitted over physical cables (Ethernet, fiber optic) or wirelessly using radio waves (Wi-Fi, Bluetooth).

6. Protocols:

   • These are standardized rules that define how data is transmitted over a network. Common protocols include:
     • TCP/IP (Transmission Control Protocol/Internet Protocol): The foundational protocol of the Internet.
     • HTTP/HTTPS: Used for web browsing.
     • FTP: Used for file transfers.
     • SMTP: Used for email.

Networking Models:

1. Client-Server Model:

   • In this model, a server provides resources, data, or services, and clients request access to these resources.
   • Example: A web server hosting a website that users access via a browser.

2. Peer-to-Peer (P2P) Model:

   • In P2P networking, each device (peer) can act as both a client and a server, sharing files and resources directly with other devices.
   • Example: File-sharing services like BitTorrent.

Network Topologies:

1. Star Topology:
   • Devices are connected to a central hub or switch. If one device fails, it doesn’t affect the rest of the network.
2. Bus Topology:
   • All devices share a single communication line. If the line fails, the entire network goes down.
3. Ring Topology:
   • Devices are connected in a circular fashion. Data travels in one direction around the ring.
4. Mesh Topology:
   • Every device is connected to every other device. It provides redundancy but is costly and complex.

Benefits of Computer Networking:

• Resource Sharing: Devices can share resources like printers, storage, and software.
• Communication: Enables users to communicate through email, messaging, and video conferencing.
• Centralized Data Management: Data can be stored and managed in a centralized location.
• Scalability: Networks can be easily expanded by adding more devices.
• Security: Centralized control helps in managing access and protecting sensitive data.

Computer networking is essential for modern businesses, homes, and institutions, making it easier to share information, collaborate, and access the Internet.