Data compression is the compacting of info by lowering the number of bits that are stored or transmitted. In this way, the compressed info takes considerably less disk space than the initial one, so more content could be stored using the same amount of space. You can find different compression algorithms which function in different ways and with many of them just the redundant bits are removed, so once the info is uncompressed, there is no loss of quality. Others delete unneeded bits, but uncompressing the data following that will result in lower quality compared to the original. Compressing and uncompressing content needs a large amount of system resources, in particular CPU processing time, therefore every hosting platform which uses compression in real time needs to have enough power to support this attribute. An example how information can be compressed is to replace a binary code such as 111111 with 6x1 i.e. "remembering" how many sequential 1s or 0s there should be instead of saving the actual code.