Understanding Networks

• Networks are interconnected systems providing a means for sharing resources such as files, internet connection, printers, and software.
• There are two types of networks: Local Area Network (LAN) and Wide Area Network (WAN). LANs connect devices within a single location, while WANs connect devices over a large geographical area.
• Networks can be wired or wireless. Wired networks use cables while wireless networks use radio signals or infrared light.

Network Components

• Servers are powerful computers that provide services like email, web hosting, file storage, and print services to other computers in the network.
• Clients are devices that request services from the server.
• Hub, switch, and router are networking devices. A hub broadcasts all data to every device, a switch sends data only to the intended device, and a router moves data across networks.
• Transmission media includes twisted pair, coaxial cable, fiber-optic cable for wired networks, and airwaves for wireless networks.

Network Technologies and Protocols

• Ethernet is the most common type of network technology used in LANs.
• The Internet Protocol (IP) is responsible for routing data across networks. It works alongside the Transmission Control Protocol (TCP) which ensures data is reliably delivered.
• Wireless technologies include Wi-Fi for short-range wireless connections and LTE/4G/5G for long-range wireless connections.
• Internet Service Providers (ISPs) provide homes and businesses with access to the internet via various technologies (DSL, Fibre, 4G/5G, Satellite).

Network Security and Challenges

• Firewalls are used to control incoming and outgoing network traffic based on predetermined security rules.
• Encryption is the process of encoding data to prevent unauthorized access.
• Network attacks could be passive (eavesdropping, traffic analysis) or active (man-in-the-middle, denial of service).
• Malware (virus, worm, trojan) are malicious software designed to harm or exploit any computing device or network.
• Challenges in networking include securing data, managing traffic, and configuring network for optimum performance.

Network Management

• Network management involves overseeing, controlling, and troubleshooting network's operation and performance.
• Network administrators use monitoring tools to check for issues like slowing or failing components.
• They use various models and protocols such as SNMP (Simple Network Management Protocol) for managing and monitoring the network.
• Backup and recovery are key aspects of network management. This ensures data is safe and can be retrieved in case of a loss.