The term data compression means reducing the number of bits of info that has to be stored or transmitted. You can do this with or without losing information, which means that what will be deleted at the time of the compression will be either redundant data or unneeded one. When the data is uncompressed subsequently, in the first case the information and its quality will be the same, while in the second case the quality will be worse. You can find various compression algorithms that are more efficient for various type of data. Compressing and uncompressing data generally takes lots of processing time, so the server carrying out the action should have plenty of resources in order to be able to process your info fast enough. One simple example how information can be compressed is to store how many sequential positions should have 1 and how many should have 0 inside the binary code as an alternative to storing the actual 1s and 0s.