Computer Networks Fundamentals

Computer Networks

Definition

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

Network Types

• LAN (Local Area Network): Connects devices in a limited geographical area (e.g., home, office building).
• WAN (Wide Area Network): Covers a larger geographical area (e.g., city, country).
• MAN (Metropolitan Area Network): Connects devices in a metropolitan area (e.g., university campus).
• WLAN (Wireless Local Area Network): Wireless network that connects devices in a limited area.

Network Topologies

• Physical Topology: Refers to the physical layout of devices and connections.
• Logical Topology: Refers to the way data is transmitted between devices.
• Common Topologies:
  • Bus
  • Star
  • Ring
  • Mesh

Network Protocols

• TCP/IP (Transmission Control Protocol/Internet Protocol): Suite of protocols used for communication on the internet.
• HTTP (Hypertext Transfer Protocol): Protocol for transferring data over the web.
• FTP (File Transfer Protocol): Protocol for transferring files over a network.

Network Devices

• Hub: Simple network device that connects multiple devices.
• Switch: Network device that filters and forwards data packets.
• Router: Device that connects multiple networks and routes data packets.
• Gateway: Device that connects a network to the internet.

Network Security

• Firewall: System that controls incoming and outgoing network traffic.
• Encryption: Process of converting plaintext data into unreadable ciphertext.
• Authentication: Process of verifying the identity of users or devices.

Network Threats

• Malware: Software designed to harm or exploit a network.
• Virus: Type of malware that replicates itself.
• Worm: Type of malware that spreads without user interaction.
• DDoS (Distributed Denial of Service): Attack that overwhelms a network with traffic.