What is Networking?
Computer networking is the practice of connecting computers and other devices together to share resources and communicate. Every time you browse the web, send an email, or stream a video, you're using a computer network.
Why Learn Networking?
Understanding networking is essential for:
- System administrators who manage servers and infrastructure
- Developers building distributed applications
- Security professionals protecting systems from attacks
- Anyone in IT who troubleshoots connectivity issues
Types of Networks
Networks come in different sizes and scopes:
Local Area Network (LAN)
A LAN connects devices in a limited area like a home, office, or building. Your home WiFi network is a LAN.
Simple LAN (Local Area Network)
Wide Area Network (WAN)
A WAN spans a large geographic area, connecting multiple LANs together. The internet is the largest WAN in existence.
WAN Connection (Two Sites)
Other Network Types
- MAN (Metropolitan Area Network) - Covers a city
- PAN (Personal Area Network) - Your phone connecting to Bluetooth devices
- VPN (Virtual Private Network) - Secure tunnel over public networks
How Data Travels
When you request a webpage, here's a simplified version of what happens:
- Your device creates a request with the destination address
- The request is broken into packets (small chunks of data)
- Packets travel through routers that forward them toward the destination
- The destination server reassembles packets and sends a response
- Your device receives the response and displays the webpage
How Data Travels Through the Network
1. Application Layer
You type a URL in your browser. The browser creates an HTTP request.
Think of it like sending a letter: you need an address (IP address), a delivery service (routers), and a return address so replies can find you.
Key Concepts You'll Learn
Throughout this course, we'll cover:
- The OSI Model - A framework for understanding network layers
- IP Addressing - How devices are identified on networks
- Protocols - Rules that govern network communication
- Switching and Routing - How data finds its path
Practice Challenges
Find Your Public IP
Your public IP address is how the internet sees you. It's assigned by your ISP and is shared by all devices on your network (through NAT).
Find Your Private IP
Your private IP is your address within your local network. Each device on your home network has a unique private IP.
Additional Tasks
Observation: Identify at least 3 devices connected to your home network. These could be phones, tablets, smart TVs, gaming consoles, or IoT devices.
Concept Check: Can you explain the difference between a LAN and a WAN to someone else? Try explaining it in your own words.
Summary
Networking connects devices to share resources and communicate. Understanding these fundamentals will help you troubleshoot issues, build better applications, and secure your systems.
In the next lesson, we'll explore the OSI Model - a conceptual framework that breaks down networking into seven distinct layers.