An audio player is a kind of media player for playing back digital audio, including optical discs such as CDs, SACDs, DVD-Audio, HDCD, audio files and streaming audio. In addition to VCR-like functions like playing, pausing, stopping, rewinding, and forwarding, some common functions include playlisting, tagging format support, and equalizer. Many of the audio players also support simple playback of digital videos in which we can also run movies. An audio file format is a file format for storing audio data on a computer system. It can be a raw bitstream, but it is usually a container format or an audio data format with defined storage layer. The general approach towards storing digital audio is to sample the audio voltage which, on playback, would correspond to a certain level of signal in an individual channel with a certain resolution the number of bits per sample in regular intervals. This data can then be stored uncompressed, or compressed to reduce the file size.