Computer Networks Overview

Flashcards covering essential concepts in computer networks, including definitions, types, advantages, and threats.

What is a Network?

A network is two or more computers joined together to communicate and share resources.

What is the Internet?

The Internet is a global network connecting millions of computers worldwide, invented in 1983.

Personal Area Network (PAN)

A small network typically used for personal devices like smartphones and laptops, e.g., Bluetooth connections.

Local Area Network (LAN)

A network limited to a small geographic area such as a home, school, or office, e.g., school computer labs.

Metropolitan Area Network (MAN)

Covers a larger area such as a city and connects multiple LANs, e.g., city-wide Wi-Fi.

Wide Area Network (WAN)

Spans a large geographical area, often connecting different cities or countries, e.g., the Internet.

Star Topology

A network layout where devices connect to a central hub or switch.

Bus Topology

A network layout where all devices share a single central cable.

Ring Topology

Devices are connected in a circular fashion.

Mesh Topology

Every device connects directly to multiple other devices.

Analog Signal

Continuous waves used in older communication methods like radio signals.

Digital Signal

Uses binary code (0s and 1s) and is more reliable and efficient than analog.

Simplex Mode

Data flows in one direction only, e.g., radio broadcasts.

Half Duplex Mode

Data flows in both directions, but only one at a time, e.g., walkie-talkies.

Full Duplex Mode

Data flows in both directions simultaneously, e.g., telephone calls.

Twisted Pair Cable

Two wires twisted together, used in LANs and telephones, e.g., Ethernet cable.

Coaxial Cable

Thicker copper cable that transmits data 8-10 times faster than twisted pair cables.

Fiber Optic Cable

Uses light signals rather than electromagnetic waves for very fast data transmission.

Advantages of Networks

Information sharing, resource sharing, access control, flexibility, and collaboration.

Disadvantages of Networks

Can be expensive to install, time-consuming, server failures, and security risks.

Advantages of the Internet

Global communication, vast access to information, e-commerce, and social connectivity.

Disadvantages of the Internet

Cyber threats, misinformation, privacy concerns, and addiction.

Viruses & Malware

Infect systems, causing damage to computers and networks.

Phishing Attacks

Fraudulent attempts to steal data or personal information from users.

Denial-of-Service (DoS) Attacks

Overloading a network to crash services and disrupt access.

Data Interception

Unauthorized access to transmitted data between computers.

Spyware

Software that monitors user activity often without their consent.

Ransomware

Malware that locks data and demands a ransom for its release.