1️⃣ What is a Network?
Definition:
A network is a group of devices that connect to share information, resources, or services.
Real-Life Example:
Key Idea:
The purpose of a network is communication. Without communication, there’s no network.
2️⃣ Types of Networks (Scope and Scale)
Type | Description | Example |
PAN (Personal Area Network) | Smallest, for personal devices | Phone + Smartwatch via Bluetooth |
LAN (Local Area Network) | Connects devices in a small area | Office or home Wi-Fi |
WLAN (Wireless LAN) | LAN without wires | Wi-Fi in coffee shops or offices |
MAN (Metropolitan Area Network) | Connects multiple LANs in a city | University campus network |
WAN (Wide Area Network) | Large networks across cities/countries | Internet, corporate branch connections |
3️⃣ Networking Devices and Their Roles
4️⃣ IP Addressing (The “House Number” of a Device)
Subnetting :
5️⃣ OSI & TCP/IP Models (How Data Travels)
Think of this as “the path data takes” from your computer to another device.
Layer | OSI | Simple Explanation | Example |
1 | Physical | The cables, Wi-Fi signals, electrical signals | Ethernet cable, Wi-Fi |
2 | Data Link | Identifies devices in same network using MAC addresses | Switch forwards frames |
3 | Network | IP addressing and routing between networks | Router forwards packets |
4 | Transport | Ensures reliable delivery | TCP handshake, UDP for streaming |
5-7 | Application | Software, apps, and protocols | Browsers, email, DNS queries |
