Computer Networks Overview

Computer Networks

• 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.
• They enable resource sharing of items like printers, files, and internet connections.

Types of Computer Networks

• Local Area Network (LAN): Connects computers within a small area, like 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 large geographical areas, using leased telecommunication lines. The internet is the largest WAN.
• Wireless Networks: Networks like Wi-Fi and Bluetooth are essential for mobile connectivity.

Networking Devices

• Router: Directs data between networks, enabling internet access.
• Switch: Connects devices within a network and filters data to the correct destination.
• Modem: Converts digital data to analog signals 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.

Introduction to the Internet

• 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 and transmitted over networks, then reassembled on arrival.

Internet Protocols

• Internet Protocol (IP): Manages addressing and routing of packets across networks.
• Transmission Control Protocol (TCP): Ensures reliable delivery of packets across networks.
• 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 emails.

IP Addresses and Domain Names

• 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 (e.g., google.com) into IP addresses.
• IPv4: 32-bit address, limited in availability, uses four octets separated by periods.
• IPv6: 128-bit address, created to handle the expansion of internet-connected devices, uses hexadecimal characters.

Internet Services and Applications

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

Cybersecurity in Networking

• Network Security: Protects data and resources from cyber threats.
• 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.
• DDoS: Overloads servers with traffic, causing a shutdown.
• Security Measures: Use of firewalls, antivirus software, encryption, and two-factor authentication (2FA).

This quiz covers the fundamentals of computer networks, including their purpose and various types such as LAN, MAN, WAN, and wireless networks. It also discusses essential networking devices like routers and switches that facilitate data exchange and resource sharing. Test your knowledge of how different networks operate and their components.