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, and enable resource sharing (e.g., printers, files, internet).

Types of Computer Networks

• Local Area Network (LAN): Connects computers within a small area, like an office, typically private.
• Wide Area Network (WAN): Covers a large geographic area (e.g., cities, countries) using leased telecom lines; the internet is the largest WAN.
• Metropolitan Area Network (MAN): Connects networks within a city, often used by businesses or government.

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 for transmission over phone lines.
• Access Point: Provides wireless connectivity within a network.
• Firewall: Security device that controls network traffic to prevent unauthorized access.

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, becoming commercialized in the 1990s.
• Data is broken into packets, transmitted over networks, and 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.
• 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 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: A 32-bit address, now limited in availability. Comprised of four octets separated by periods, each octet ranging from 0 to 255.
• IPv6: A 128-bit address designed to accommodate the expanded number of internet-connected devices. Represented by 8 groups of 4 hexadecimal characters.

Internet Services and Applications

• 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 sharing content.

Cybersecurity in Networking

• Network security is crucial to protect 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, demanding a ransom.
• DDoS: Overloads servers with traffic, causing a shutdown.
• Security Measures: Use firewalls, antivirus software, encryption, and two-factor authentication (2FA).

Future Trends in Networking and the Internet

• 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 in Networking: AI improves network efficiency, security, and troubleshooting.
• Quantum Networking: Future technology for highly secure communication using quantum mechanics.