Describe how data moves around a network
A network exists when you have two or more devices that share data. As you saw in the previous unit, a network is composed of many different physical parts that work together to ensure your data gets to where it’s needed. This transmission of data across a network is enabled by a suite of communication protocols, often referred to as TCP/IP. It’s named after the two main protocols: Transmission Control Protocol (TCP), which handles the connection between two devices, and Internet Protocol (IP), which is responsible for routing information across the network.
Every network on the planet shares and moves data every second of the day. This data comes in every shape and size, from a simple message to images, and even the movies that are streamed to your home.
The datagram or packet
Networks exist to help make device-to-device or system-to-system communication easier. Whatever the size of data, it all needs to be broken down into tiny, uniform chunks. These chunks are called datagrams but are also more commonly known as packets.
Imagine that you want to stream a movie to your device. Given the enormous size of the data involved, the streaming server can’t give you the whole movie in one go. Instead, the movie is broken up into billions of packets. Each packet contains a small part of the movie, which is then sent to your device. Your device has to wait until enough packets have been received before you can start watching the movie. In the background, the server continues to send a steady stream of packets to your device just ahead of what’s being displayed. If your network speed slows down, then the packets may not reach you in time. The picture you see might become distorted or blocky and there may be gaps in the sound.