Types of Computer Networks

Study Notes

A computer network is a group of interconnected computers and devices that communicate to share resources and data.
The purpose of computer networks is to facilitate data exchange and communication, and enable resource sharing like printers, files, and internet connections.
Examples include:
- Local Area Network (LAN): Within a single building.
- Wide Area Network (WAN): Across large areas (cities or countries).
- Metropolitan Area Network (MAN): Covers a city or campus area.

Local Area Network (LAN): Connects computers within a small area, such as an office, and is typically private.
Metropolitan Area Network (MAN): Connects networks within a city, often used by businesses or government.
Wide Area Network (WAN): Covers a large geographic area, often using leased telecom lines, and the internet is the largest WAN.
Wireless Networks: Examples include Wi-Fi and Bluetooth, essential for mobile connectivity.

Router: Directs data between networks, enabling internet access.
Switch: Connects devices within a network, filtering data to the correct destination.
Modem: Converts digital data for transmission over phone lines.
Access Point: Provides wireless connectivity within a network.
Firewall: A security device that controls network traffic to prevent unauthorized access.

The internet is a vast network connecting millions of private, public, academic, and business networks globally.
It originated from ARPANET in the 1960s and became commercialized in the 1990s.
Data is broken into packets, transmitted over networks, and reassembled on arrival.

Internet Protocol (IP): Manages addressing and routing of packets across networks.
Transmission Control Protocol (TCP): Ensures reliable delivery of packets.
Hypertext Transfer Protocol (HTTP/HTTPS): Governs web communication and security (HTTPS).
File Transfer Protocol (FTP): Used for transferring files over the internet.
Email Protocols (SMTP, POP3, IMAP): Manage sending and receiving email.

IP Address: A unique identifier assigned to each device on a network (e.g., 192.168.1.1).
Domain Name System (DNS): Translates human-friendly domain names (like google.com) into IP addresses.
IPv4: 32-bit address, limited in availability. Example: 192.168.0.1, uses four octets (numbers from 0 to 255).
IPv6: 128-bit address, created to handle the expansion of internet-connected devices. Example: 2001:0db8:85a3:0000:0000:8a2e:0370:7334, uses eight groups of four hexadecimal characters.

World Wide Web (WWW): A collection of websites and web pages accessible via the internet.
Email: Digital communication through electronic mail services.
Cloud Computing: Accessing and storing data online rather than locally.
Social Media and Streaming Services: Platforms for interaction, entertainment, and content sharing.

Network Security: Protects data and resources from cyber threats.
Common Threats: Include Malware (malicious software designed to damage or exploit devices), Phishing (fraudulent attempts to gather sensitive information), Ransomware (malware that encrypts data and demands a ransom), and DDoS (distributed denial-of-service attacks that overload servers with traffic, causing a shutdown).
Security Measures: Include the use of firewalls, antivirus software, encryption, and two-factor authentication (2FA).

5G and Beyond: Next-generation cellular networks that enable faster data transmission.
Internet of Things (IoT): Network connectivity extending to everyday objects, allowing data exchange.
Artificial Intelligence (AI) in Networking: AI improves network efficiency, security, and troubleshooting.
Quantum Networking: Future technology for highly secure communication using quantum mechanics.