Computer Networks
Learn how computers connect and communicate with each other through wired and wireless networks.
What is a Computer Network?
A computer network is a group of interconnected devices that can communicate and share resources. Networks can be as small as two computers in a home or as large as the global internet connecting billions of devices.
Types of Networks
- LAN (Local Area Network) — Covers a small area like a home, office, or campus. High speed, low latency.
- WAN (Wide Area Network) — Spans large geographic areas. The internet is the world's largest WAN.
- MAN (Metropolitan Area Network) — Covers a city or large campus.
- PAN (Personal Area Network) — Very short range (Bluetooth, USB). Around a single person.
- WLAN (Wireless LAN) — A LAN using Wi-Fi instead of cables.
Network Topologies
The physical or logical arrangement of devices in a network:
- Star — All devices connect to a central switch/router. Most common in homes.
- Bus — All devices share a single cable. Simple but collision-prone.
- Ring — Devices form a circular chain. Used in some industrial networks.
- Mesh — Every device connects to every other. Very reliable, used in critical systems.
Key Networking Concepts
- IP Address — A unique identifier for each device on a network (e.g., 192.168.1.1).
- MAC Address — A hardware identifier burned into every network card.
- Router — Forwards data packets between different networks.
- Switch — Connects devices within the same network.
- Bandwidth — Maximum data transfer rate (e.g., 100 Mbps).
- Latency — Time for a packet to travel from source to destination.
- Protocol — Agreed-upon rules for how data is formatted and transmitted.
Network Models
Two important reference models describe how networks work:
- OSI Model — 7 layers from physical cables to applications. See OSI Model.
- TCP/IP Model — 4 layers. The practical model the internet uses. See TCP/IP.
What's Next?
Dive deeper with OSI Model to understand the 7 network layers, or learn how web traffic works with HTTP & HTTPS.