Networks Part I — Basics, Types, and How Devices Communicate

A network is simply a group of connected computers and devices that can communicate and share resources. From your home Wi-Fi to the global internet, networks enable messaging, streaming, printing, remote control, and more.

In this lesson you’ll learn why we need networks, the difference between LAN and WAN, and how devices communicate via Ethernet, Wireless, Protocols, and Wi-Fi.

🔹 1️⃣ What is a Network?

• Network: a group of connected computers and devices.
• At home, your phones, laptops, smart TV, and tablet join the same network after you enter the Wi-Fi password.
• Devices on the same network can communicate and share resources (e.g., cast a video from your phone to your TV, print from your laptop).

🔹 2️⃣ Why Do We Need Networks?

• Share files, printers, and internet access.
• Communicate (messages, calls, streaming).
• Control smart devices (TV, speakers, lights) from your phone.
• Collaborate at school, work, or across locations.

🔹 3️⃣ Network Types

At this level we will study Two main categories for now: LAN and WAN.

🏠 LAN — Local Area Network

• A nearby group of connected devices (home, classroom, office, hospital).
• Can range from a few devices (home) to hundreds (campus building).
• Big organizations can have multiple LANs (e.g., one per building).

🌍 WAN — Wide Area Network

• Many LANs connected across cities, countries, or the world.
• WANs can connect thousands or millions of devices.
• The internet is the biggest WAN.

🔹 4️⃣ How Do Computers Communicate on a LAN?

Communication happens over wired or wireless connections, following agreed rules called protocols:

• Ethernet (wired): rules for sending data through cables (e.g., via a switch or router).
• Wireless: rules for sending data through radio signals; common form is Wi-Fi.
• Protocol: a standard set of rules defining how devices format, send, and receive data so everything understands each other. the language/rules devices follow to communicate.
• Wi-Fi (Wireless Fidelity): a popular wireless method to connect to a network. radio-based LAN rules.
• Router: connects your LAN to the outside (internet/other networks).
• Switch: interconnects devices inside the LAN.

In practice, a router connects your LAN to other networks (and the internet), while a switch efficiently interconnects devices inside your LAN.

🔗 Interconnection

• Network = connected devices that communicate and share resources.
  
• LAN (local) vs WAN (wide) → scope & distance differ; WANs interconnect many LANs.
• Ethernet (wired) and Wi-Fi (wireless) use protocols (rules) so devices understand each other.

By understanding these links, learners can map home and school setups to the larger internet and reason about how data flows end-to-end. 🚀