Data compression is the compacting of data by lowering the number of bits that are stored or transmitted. As a result, the compressed information requires substantially less disk space than the initial one, so additional content might be stored on identical amount of space. You will find various compression algorithms which function in different ways and with a number of them just the redundant bits are erased, therefore once the data is uncompressed, there is no decrease in quality. Others erase unneeded bits, but uncompressing the data at a later time will lead to lower quality in comparison with the original. Compressing and uncompressing content requires a significant amount of system resources, in particular CPU processing time, so every Internet hosting platform that uses compression in real time must have sufficient power to support that feature. An example how data can be compressed is to substitute a binary code such as 111111 with 6x1 i.e. "remembering" the number of consecutive 1s or 0s there should be instead of keeping the entire code.