Networking Basics

✅ What is Computer Networking?

A computer network is a group of connected devices (like computers, smartphones, servers) that share data, resources, and communicate with each other.

👉 Networking allows devices to:

• Share files and printers.

• Access the internet.

• Communicate via email, chat, and video calls.

• Connect to remote servers (cloud, websites).

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🌐 Types of Networks

Type	Description	Example
LAN (Local Area Network)	Small network in one location (office, home).	Wi-Fi at home, office network.
WAN (Wide Area Network)	Large network connecting multiple locations.	The Internet, corporate networks.
MAN (Metropolitan Area Network)	Covers a city or large campus.	City-wide public Wi-Fi.
PAN (Personal Area Network)	Small network around a person.	Bluetooth devices, smartwatch to phone.

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📶 Basic Networking Components

Component	Role	Example
Router	Connects devices to the internet, manages traffic.	Home Wi-Fi router.
Switch	Connects devices in a network, sends data to correct device.	Office network switch.
Modem	Connects to the ISP (Internet Service Provider).	Fiber or cable modem.
Access Point	Extends Wi-Fi range.	Wi-Fi extender in large homes.
Firewall	Protects network from attacks.	Hardware firewall or Windows Firewall.
Server	Provides services (web, mail, file sharing).	Google servers for Gmail.

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🛜 Common Networking Devices:

Device	Description
Computer/PC	Connects to network to send/receive data.
Smartphone	Accesses internet and apps via Wi-Fi/mobile data.
Printer (Networked)	Shared by multiple users over the network.
Smart TV	Streams content over the internet.

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📊 Networking Protocols (Languages for Communication):

Protocol	Purpose
HTTP/HTTPS	Web browsing (secure).
FTP (File Transfer Protocol)	File sharing and transfer.
TCP/IP (Transmission Control Protocol/Internet Protocol)	Basic internet communication rules.
DNS (Domain Name System)	Translates domain names (like google.com) to IP addresses.
DHCP (Dynamic Host Configuration Protocol)	Assigns IP addresses to devices automatically.
SMTP/IMAP/POP3	Email sending/receiving.

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🔑 Key Networking Terms to Know:

Term	Meaning
IP Address	Unique number assigned to each device on a network. (e.g., 192.168.1.1)
MAC Address	Unique hardware address of network card.
SSID	Name of a Wi-Fi network.
Bandwidth	Maximum data transfer rate (e.g., 100 Mbps).
Firewall	Security system that controls incoming/outgoing traffic.
VPN (Virtual Private Network)	Secure, private connection over the internet.
Ping	Test network connection to another device.

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🔗 How Internet Works (Simplified Flow):

1. Device (Laptop/Phone) connects to Router via Wi-Fi.

2. Router connects to Modem.

3. Modem connects to ISP (Internet Service Provider).

4. ISP connects to the Internet.

5. Request goes to Web Server (e.g., Google) and returns results.

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🔒 Network Security Basics:

Issue	Solution
Unauthorized Access	Set strong Wi-Fi passwords, enable WPA3.
Viruses, Malware	Use firewalls, antivirus software.
Data Interception	Use VPN, HTTPS websites.
Phishing Attacks	Educate users, use email filters.

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⚙️ Basic Network Troubleshooting Steps:

1. Check device connection (Wi-Fi/Ethernet).

2. Restart router/modem.

3. Check IP address (cmd: ipconfig in Windows).

4. Ping test (cmd: ping google.com).

5. Check if only one device or all devices are affected.

6. Contact ISP if the internet is down.

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✅ Summary (In Simple Words):

Computer networking connects devices to share information, resources, and internet access. Tools like routers, switches, and modems help devices talk to each other. Common problems can often be fixed by restarting equipment or checking connections.