Compression deals with techniques for reducing the consumption of expensive resources.  Data compression can be lossless or lossy. Lossless compression algorithms usually exploit statistical redundancy in such a way as to represent the sender's data more concisely without error. lossy compression is a data encoding method which discards (loses) some of the data, in order to achieve its goal, that decompressing the data yields content that is different from the original, though similar enough to be useful in some way.