Data compression is the compacting of info by decreasing the number of bits which are stored or transmitted. In this way, the compressed info will need much less disk space than the initial one, so extra content can be stored using identical amount of space. You can find different compression algorithms that work in different ways and with some of them only the redundant bits are removed, which means that once the info is uncompressed, there is no decrease in quality. Others delete excessive bits, but uncompressing the data afterwards will lead to lower quality compared to the original. Compressing and uncompressing content needs a significant amount of system resources, particularly CPU processing time, therefore every hosting platform that employs compression in real time should have ample power to support that feature. An example how data 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 keeping the actual code.