Networks & Topologies
Introduction to Computer Networks
A computer network is a system of interconnected computers and devices that can communicate and share resources such as files, printers, and internet connections. Networks can range from small local setups to the vast, global infrastructure of the internet.
Classification: Network Types & Topologies
- PAN (Personal Area Network): Smallest range (e.g., Bluetooth connecting a phone to a headset).
- LAN (Local Area Network): Covers a small geographic area like a home, office, or building.
- MAN (Metropolitan Area Network): Connects users within a specific city or large campus.
- WAN (Wide Area Network): Spans large distances, even across countries and continents (e.g., the Internet).
The Network Topologies Master Table
| Topology | Arrangement / Logic | Key Fact |
|---|---|---|
| Bus | Single central cable | If the main cable fails, the network fails |
| Star | Connected to a central Hub/Switch | Most common in modern LANs |
| Ring | Each device has two neighbors | Data travels in one direction (Token) |
| Mesh | Every device is interconnected | Highest reliability / redundancy |
| Tree | Hierarchical / Star-Bus hybrid | Easy to expand but complex to manage |
Key Scientific Facts
- The Internet is essentially a network of networks, using the TCP/IP suite to communicate.
- A Router is a device that directs data packets between different networks (e.g., your home LAN and the Internet).
- A Switch is an intelligent device used within a LAN to connect multiple devices and transmit data to the specific target port.
- Ethernet is the most common technology for wired local area networks.
- Bandwidth refers to the maximum data transfer rate of a network connection, usually measured in bits per second (bps).
Subject Card Prompts (Flashcards)
- Q: What is the full form of 'LAN'?
- A: Local Area Network.
- Q: Which network topology requires a central hub or switch?
- A: Star Topology.
- Q: What is the global system of interconnected computer networks called?
- A: The Internet.
- Q: Which device is used to connect a computer to a telephone line for internet access?
- A: Modem.
Practice MCQ
"Which type of network spans the largest geographic area, often connecting different cities or even countries?"
A) LAN
B) PAN
C) MAN
D) WAN
(Correct: D - WAN)