This topic will cover the basics of computer networking, including the definition of computer networking, its importance, and the types of networks such as LAN, WAN, and MAN.
Introduction to Computer Networking
(A concise, structured overview for quick study and reference)
1. What Is a Computer Network?
- Definition: A collection of interconnected devices (computers, servers, phones, IoT gadgets, etc.) that can share data, resources, and services.
- Primary Goals
- Communication: Enable devices to exchange information.
- Resource Sharing: Printers, files, applications, internet connection.
- Scalability & Flexibility: Add or remove nodes without disrupting the whole system.
2. Key Terminology
| Term |
Meaning |
| Node |
Any device (host, router, switch, etc.) that participates in the network. |
| Link |
Physical or logical connection between two nodes (cable, wireless link, virtual tunnel). |
| Protocol |
A set of rules governing data exchange (e.g., TCP, HTTP). |
| Topology |
Physical or logical layout of the network (star, mesh, bus, ring). |
| Bandwidth |
Maximum data rate a link can carry (bits per second). |
| Latency |
Time for a packet to travel from source to destination (ms). |
| Throughput |
Actual data transferred over a period of time (often lower than bandwidth). |
| IP Address |
Numerical identifier for a device at the network layer (IPv4/IPv6). |
| MAC Address |
Hardware address of a network interface card (layer‑2). |
3. Network Types by Scope
| Scope |
Typical Size |
Example Environments |
| PAN (Personal Area Network) |
< 10 m |
Bluetooth headphones, smartwatches. |
| LAN (Local Area Network) |
Building or campus |
Office Ethernet, university dorms. |
| MAN (Metropolitan Area Network) |
City‑wide |
Municipal fiber, cable TV networks. |
| WAN (Wide Area Network) |
Country/Global |
The Internet, corporate MPLS networks. |
| CAN (Campus Area Network) |
Multiple LANs in a campus |
University campus, corporate park. |
| SAN (Storage Area Network) |
Specialized storage |
Fibre Channel storage clusters. |
4. Network Architecture Layers
4.1 OSI Model (Conceptual)
| Layer |
Primary Function |
Typical Protocols |
| 7 – Application |
End‑user services |
HTTP, FTP, SMTP |
| 6 – Presentation |
Data format & encryption |
TLS, JPEG, ASCII |
| 5 – Session |
Dialog control |
NetBIOS, RPC |
| 4 – Transport |
End‑to‑end reliability |
TCP, UDP |
| 3 – Network |
Routing & logical addressing |
IP, ICMP |
| 2 – Data Link |
Frame handling, MAC addressing |
Ethernet, PPP |
| 1 – Physical |
Bits on media |
Twisted‑pair, fiber, radio |
4.2 TCP/IP Model (Practical)
| Layer |
OSI Equivalent(s) |
Core Protocols |
| Application |
5‑7 |
HTTP, DNS, SSH |
| Transport |
4 |
TCP, UDP |
| Internet |
3 |
IPv4, IPv6, ICMP |
| Link (Network Access) |
1‑2 |
Ethernet, Wi‑Fi, ARP |
5. Common Network Devices
| Device |
Role |
Typical Placement |
| Hub |
Broadcasts incoming frames to all ports (no intelligence) |
Small LANs (legacy) |
| Switch |
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