Networks || GCSE

• A network is a group of devices connected together so they can communicate with eachother and share resources.

  
• To access a network, you need a device with a network interface card. You will also need a software that allows your device to communicate which is usually built into your devices system.
• The two main types of networks are local area networks (LAN) and wide area networks (WAN).
• Local Area Networks (LAN): A LAN connects computers within the same building or campus. They use cables such as Ethernet cables to transmit data between devices.
• Wide Area Networks (WAN): WAN's cover larger areas than LAN's. They often span multiple buildings or even countries. They use telephone lines, fibre optic cables and satellite links to transmit data over long distances.
• Network topology refers to how the components of a computer network are arranged physically.
• Network Topology refers to how all the components of a computer network are arranged. There are three common topologies used today - Bus, Star and Ring.
• Bus Topology: All devices on this type of network are connected by one cable called a bafkbone. Each device has its own connector on the backbone. This means that if any part of the bus breaks down then no other parts of the network can be accessed.
• Star Topology - Devices are all connected to a central hub using individual cables. This makes it easy to add new devices to the network but if the hub fails then the whole network goes down.
• Ring Topology - Similar to star topology except there is no central hub. Instead, each device is connected to two other devices forming a ring. Data flows around the ring in only one direction.
• A router is a hardware device which manages traffic flow across different networks. It does this by forwarding packets of information along the most efficient route available at any given time.
• The Internet is a global collection of interconnected networks which allows users from different locations to communicate with each other via email, web browsers etc.
• The Internet Protocol (IP) address is a unique number assigned to every device on an IP-based network such as the internet. The format consists of four numbers separated by dots with each number ranging from 0 to 254.
• TCP/IP stands for Transmission Control Protocol / Internet Protocol
• TCP (Transmission Control Protocol) ensures reliable data transmission between computers over an IP network such as the internet.
• An IPv6 address is a unique identifier assigned to each device on an IP-based network. Unlike IPv4 addresses, they consist of eight groups of four hexadecimal digits separated by colons. They also have more possible combinations than IPv4 so will last longer.
• HTTPS is a secure version of HTTP where data sent between your browser and website is encrypted so that it cannot be read or tampered with by third parties.