Computer Networks: Definition and Types

Computer Networks

Definition and Types

• A computer network is a set of interconnected devices that communicate with each other to share resources and exchange data.
• Types of computer networks:
  • LAN (Local Area Network): connects devices in a limited geographical area.
  • WAN (Wide Area Network): connects devices over a larger geographical area.
  • MAN (Metropolitan Area Network): connects devices in a metropolitan area.
  • WLAN (Wireless Local Area Network): connects devices wirelessly.
  • Wi-Fi: a type of WLAN that uses radio waves to connect devices.

Network Topology

• Physical topology: the physical arrangement of devices and connections.
• Logical topology: the way data is transmitted and received.
• Common network topologies:
  • Bus topology: a single cable connects all devices.
  • Star topology: devices connect to a central hub or switch.
  • Ring topology: devices connect in a circular configuration.
  • Mesh topology: each device connects to every other device.

Network Protocols

• Communication protocols that govern data transmission and reception.
• Common network protocols:
  • TCP/IP (Transmission Control Protocol/Internet Protocol): the most widely used protocol suite.
  • HTTP (Hypertext Transfer Protocol): used for transferring data over the internet.
  • FTP (File Transfer Protocol): used for transferring files over the internet.
  • DNS (Domain Name System): used for resolving domain names to IP addresses.

Network Devices

• Devices that facilitate communication between devices on a network:
  • Hub: a simple device that connects multiple devices.
  • Switch: a device that connects multiple devices and forwards data packets.
  • Router: a device that connects multiple networks and forwards data packets.
  • Gateway: a device that connects a network to the internet.
  • Modem: a device that converts digital signals to analog signals for transmission over phone lines.

Network Security

• Threats to network security:
  • Hacking: unauthorized access to a network.
  • Malware: malicious software that can damage a network.
  • Viruses: malicious software that replicates itself.
  • Firewalls: devices or software that block unauthorized access.
  • Encryption: the process of converting data into a code to prevent unauthorized access.

Computer Networks

• A computer network is a set of interconnected devices that communicate with each other to share resources and exchange data.

Types of Computer Networks

• LAN (Local Area Network) connects devices in a limited geographical area.
• WAN (Wide Area Network) connects devices over a larger geographical area.
• MAN (Metropolitan Area Network) connects devices in a metropolitan area.
• WLAN (Wireless Local Area Network) connects devices wirelessly.
• Wi-Fi is a type of WLAN that uses radio waves to connect devices.

Network Topology

• Physical topology refers to the physical arrangement of devices and connections.
• Logical topology refers to the way data is transmitted and received.
• Bus topology consists of a single cable that connects all devices.
• Star topology consists of devices connected to a central hub or switch.
• Ring topology consists of devices connected in a circular configuration.
• Mesh topology consists of each device connected to every other device.

Network Protocols

• TCP/IP (Transmission Control Protocol/Internet Protocol) is the most widely used protocol suite.
• HTTP (Hypertext Transfer Protocol) is used for transferring data over the internet.
• FTP (File Transfer Protocol) is used for transferring files over the internet.
• DNS (Domain Name System) is used for resolving domain names to IP addresses.

Network Devices

• Hub is a simple device that connects multiple devices.
• Switch is a device that connects multiple devices and forwards data packets.
• Router is a device that connects multiple networks and forwards data packets.
• Gateway is a device that connects a network to the internet.
• Modem is a device that converts digital signals to analog signals for transmission over phone lines.

Network Security

• Hacking is unauthorized access to a network.
• Malware is malicious software that can damage a network.
• Viruses are malicious software that replicates itself.
• Firewalls are devices or software that block unauthorized access.
• Encryption is the process of converting data into a code to prevent unauthorized access.