Network fundamentals

✅ What are Network Fundamentals?

Network fundamentals are the basic building blocks and principles that explain how computers and devices connect, communicate, and share resources over a network (locally or over the Internet).

👉 Think of it as learning how computers "talk" to each other!

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🛜 Why Networking is Important?

• Share Resources (printers, files, internet).

• Communicate (email, chat, video calls).

• Access Information (websites, databases).

• Centralized Management (corporate environments).

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⚙️ Key Elements of Network Fundamentals:

1. What is a Network?

A network is a collection of connected devices (nodes) that share data. Example: Computers, phones, printers connected via Wi-Fi or cables.

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2. Types of Networks:

Type	Size & Example
LAN (Local Area Network)	Small area (Home, Office).
WAN (Wide Area Network)	Large, global (Internet).
MAN (Metropolitan Area Network)	City-wide (Campus Wi-Fi).
PAN (Personal Area Network)	Around a person (Bluetooth).

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3. Networking Devices:

Device	Function
Router	Connects multiple networks, gives internet access.
Switch	Connects devices in a LAN and manages traffic.
Modem	Connects network to ISP (Internet Service Provider).
Access Point (AP)	Expands Wi-Fi coverage.
Firewall	Security system to block unwanted traffic.

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4. IP Address & MAC Address:

Term	Description	Example
IP Address	Logical address for identifying devices on a network.	192.168.1.2
MAC Address	Physical hardware address of a device.	00:1A:2B:3C:4D:5E

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5. Network Protocols (Communication Rules):

Protocol	Purpose
TCP/IP	Core protocol for Internet & networks.
HTTP/HTTPS	Web browsing (secure via HTTPS).
FTP	File transfers.
SMTP/IMAP/POP3	Email communication.
DNS	Translates domain names to IP (e.g., google.com → 142.250.190.78).
DHCP	Assigns IP addresses automatically.

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6. Ports and Services:

• Ports are like doors for different services (email, web).

• Example:

  • Port 80 = HTTP (Web)

  • Port 443 = HTTPS (Secure Web)

  • Port 25 = SMTP (Email)

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7. Data Transmission Methods:

Method	Description
Wired (Ethernet)	Fast, stable, uses cables (LAN).
Wireless (Wi-Fi)	Uses radio waves for mobility.
Bluetooth	Short-range personal networking.

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8. Network Topologies (How Devices Connect):

Topology	Description	Example
Star	All devices connected to a central switch/router.	Most home/office networks.
Bus	All devices share a single cable.	Early LAN setups.
Ring	Devices connected in a circle.	Some specialized networks.
Mesh	Every device connects to others.	Modern Wi-Fi mesh networks.

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9. Bandwidth & Speed:

• Bandwidth = Maximum data capacity (e.g., 100 Mbps).

• Latency = Delay in data transmission.

• Throughput = Actual speed achieved.

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🔐 Basic Network Security Concepts:

Concept	Purpose
Firewall	Blocks unauthorized access.
VPN	Encrypts connection, hides IP.
Antivirus & Anti-malware	Protects devices.
Encryption (HTTPS)	Secures data transmission.
Strong Passwords/WPA3	Protect Wi-Fi networks.

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🧠 Basic Network Troubleshooting Tools:

Tool	Purpose
Ping	Test connectivity to another device.
Traceroute (tracert)	Track path to a server.
ipconfig / ifconfig	Check IP and network config.
nslookup	Test DNS resolution.

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✅ Example: How You Access a Website (Simple Flow):

1. You type www.google.com in a browser.
2. DNS converts domain name to IP address.

3. Your device connects to Google's server via router.

4. Google sends website data back to your browser.

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🔑 Summary (In Simple Words):

Concept	Explanation
Network	Group of devices sharing data.
Router & Switch	Manage connections.
IP & MAC Address	Device identifiers.
Protocols	Rules for communication (TCP/IP, HTTP).
Firewall & VPN	Security measures.