How do computer networks (LAN, WAN, Wi-Fi) work?

 🌐 How Computer Networks Work

• At the core, computer networks work by:
• Connecting devices (computers, routers, switches, etc.)
• Transmitting data using signals (wired or wireless)
• Using protocols (rules) like TCP/IP to ensure data is sent and received correctly

🏠 1. LAN (Local Area Network)

✅ What it is:

• A network that connects devices within a small area, like a home, office, or school.

⚙️ How it works:

• Devices (computers, printers, etc.) connect through Ethernet cables or Wi-Fi to a router or switch.
• All devices share the same network and can communicate quickly and securely.

📌 Key Features:

• Feature Value
• Coverage Area Small (up to a few hundred meters)
• Speed Very fast (100 Mbps – 10 Gbps)
• Ownership Usually private (home, business)
• Example Office computers sharing a printer

🌍 2. WAN (Wide Area Network)
✅ What it is:

• A network that connects devices over large geographic areas—cities, countries, or even globally.

⚙️ How it works:

• Combines many LANs using routers, leased lines, fiber optics, or satellites.
• The Internet is the largest example of a WAN.

📌 Key Features:

• Feature Value
• Coverage Area Very large (national/global)
• Speed Varies (depends on infrastructure)
• Ownership Shared (ISPs, governments, corporations)
• Example The Internet, bank networks

📶 3. Wi-Fi (Wireless Fidelity)

✅ What it is:

• A technology that allows devices to connect to a network wirelessly using radio waves.

⚙️ How it works:

• A wireless router sends radio signals that devices like laptops and phones receive using a wireless adapter.
• The router connects to the internet (via modem), and transmits data wirelessly to connected devices.

📌 Key Features:

• Feature Value
• Connection Wireless (radio signals)
• Range Up to ~100 meters indoors
• Speed Fast (Wi-Fi 5, 6, 6E, or 7)
• Example Home Wi-Fi, public hotspots

📡 How Devices Communicate in a Network (Simplified)

• Device A wants to send data to Device B.
• Data is broken into packets.
• Packets are sent through network devices (switches, routers).
• Each packet is addressed using IP addresses.
• Device B receives, reassembles, and processes the data.

🧠 Key Network Devices

• Device Function
• Router Connects different networks, routes traffic
• Switch Connects devices in a LAN, forwards data only to the destination
• Modem Converts signals from ISP (cable/fiber/DSL) into digital form
• Access Point Provides wireless access to a wired network
• Firewall Filters traffic for security

🔐 Protocols That Make It Work

• Protocol Purpose
• TCP/IP Core internet protocol stack
• HTTP/HTTPS Web browsing
• FTP File transfers
• DNS Converts website names to IPs
• Wi-Fi (IEEE 802.11) Wireless standards

🧩 Summary Table

• Network Type Area Covered Connection Type Common Use
• LAN Local (building) Wired/Wireless Homes, offices
• WAN Large (global) Mixed (fiber, satellite) Internet, global businesses
• Wi-Fi Local (wireless) Wireless (radio waves) Wireless access within LAN