Codecs

The Codecs (shorten for "coder/decoder") is a device or program which can transform the data stream or signal. The Codecs can both code the stream/signal (for transferring, keeping or encrypting), and decode for viewing or format changing. Codecs are usually used for digital processing of video and sound.

The majority of codecs for sound and visual data uses compression with loss for the reduction of the final (compressed) file size. There are also such codecs that compress without any losses (lossless codecs), but for majority of the using the hardly noticeable improvement of quality does not justify the significant increasing of the data volume.