Computer Networks and Internet
3.1 Introduction to Computer Networks
A computer network is a group of computers connected together to share resources, exchange data, and communicate with each other.
3.2 Types of Computer Networks
- Local Area Network (LAN): A network that connects computers in a limited geographical area, such as a home, office building, or campus.
- Wide Area Network (WAN): A network that connects computers over a larger geographical area, such as a city, country, or continent.
- Metropolitan Area Network (MAN): A network that connects computers in a metropolitan area, such as a city or town.
- Wireless Network (WLAN): A network that connects computers wirelessly, using radio waves or infrared signals.
3.3 Network Topology
Network topology refers to the physical or logical arrangement of devices on a network.
- Bus Topology: A network in which all devices are connected to a single cable.
- Star Topology: A network in which all devices are connected to a central device.
- Ring Topology: A network in which devices are connected in a circular configuration.
- Mesh Topology: A network in which each device is connected to every other device.
3.4 Network Devices
- Router: A device that connects multiple networks together and routes traffic between them.
- Switch: A device that connects multiple devices within a network and forwards data packets between them.
- Hub: A device that connects multiple devices within a network and broadcasts incoming data to all connected devices.
- Modem: A device that connects a computer to the internet via a broadband connection.
3.5 Internet Basics
- Internet: A global network of interconnected computers and servers that communicate with each other using standardized protocols.
- World Wide Web (WWW): A system of interlinked hypertext documents that can be accessed via the internet.
- Web Browser: A software application that allows users to access and view web pages on the internet.
3.6 Internet Services
- Email: A service that allows users to send and receive electronic messages over the internet.
- File Transfer Protocol (FTP): A service that allows users to transfer files over the internet.
- Remote Access: A service that allows users to access and control a remote computer over the internet.
3.7 Internet Safety and Security
- Cybersecurity: The practice of protecting computer systems, networks, and sensitive information from unauthorized access, use, disclosure, disruption, modification, or destruction.
- Firewall: A network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules.
- Antivirus Software: A software program that detects, prevents, and removes malware from a computer system.
3.8 Summary
In this chapter, we learned about computer networks, including types of networks, network topology, and network devices. We also learned about the internet, including internet basics, internet services, and internet safety and security.
3.9 Exercises
1. What is the difference between a LAN and a WAN?
2. What is the function of a router in a network?
3. What is the difference between a hub and a switch?
4. How does a modem connect a computer to the internet?
5. What is the importance of cybersecurity in today's world?
3.10 Key Terms
- Computer Network
- Internet
- Network Topology
- Network Devices
- Router
- Switch
- Hub
- Modem
- Cybersecurity
- Firewall
- Antivirus Software
