🌐 Basics of Computer Networks – Overview
A computer network is a collection of interconnected devices (computers, servers, switches, routers, etc.) that communicate with each other to share data, resources, and services.
Networking forms the backbone of the modern digital world, enabling everything from emails to websites to cloud services.
🧠 Why Learn Computer Networks?
Because networks:
- Connect devices and people
- Enable internet access
- Support communication (email, VoIP, video calls)
- Enable file and resource sharing
- Form the base of cybersecurity, cloud, and IT infrastructure
🔑 Core Concepts in Computer Networks
1️⃣ Types of Networks
- LAN (Local Area Network): Small area (office, home).
- WAN (Wide Area Network): Large area (cities, countries).
- MAN (Metropolitan Area Network): City-level network.
- PAN (Personal Area Network): Bluetooth, hotspot.
2️⃣ Network Devices
- Router: Connects multiple networks, routes traffic.
- Switch: Connects devices within a LAN.
- Hub: Basic broadcast device.
- Firewall: Secures the network.
- Access Point: Provides wireless connectivity.
3️⃣ OSI & TCP/IP Models
OSI Model (7 Layers)
- Physical
- Data Link
- Network
- Transport
- Session
- Presentation
- Application
TCP/IP Model (4 Layers)
- Link
- Internet
- Transport
- Application
These models help understand how data travels through a network.
4️⃣ IP Addressing
- IPv4 (32-bit): Example – 192.168.1.1
- IPv6 (128-bit): Example – 2001:db8::1
- Public & Private IPs
- Subnet Mask
- Default Gateway
5️⃣ Network Topologies
- Bus
- Star
- Ring
- Mesh
- Hybrid
Topology defines how devices are physically/logically arranged.
6️⃣ Transmission Modes
- Simplex (One-way)
- Half-Duplex (Both ways, one at a time)
- Full-Duplex (Both ways, simultaneously)
7️⃣ Protocols
Protocols are rules for communication:
- HTTP / HTTPS
- FTP
- SMTP / POP3 / IMAP
- DNS
- DHCP
- TCP & UDP
8️⃣ Wired vs Wireless Networks
- Wired: Ethernet cables (fast & reliable)
- Wireless: Wi-Fi, Bluetooth (convenient & flexible)
9️⃣ Network Security Basics
- Firewalls
- Encryption
- VPN
- Intrusion detection/prevention
- Strong passwords
🔟 Common Networking Terms
- Bandwidth: Data transfer capacity
- Latency: Delay in transmission
- Packet: Smallest data unit
- MAC Address: Unique device identifier
- DNS: Converts domain names to IP
💼 Careers Involving Computer Networks
- Network Administrator
- Network Engineer
- Technical Support Engineer
- Cybersecurity Analyst
- Cloud Infrastructure Engineer
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