Player usually refers to software that can play video or audio files stored in the form of digital signals, and also refers to electronic equipment products with the function of playing video or audio files. For example, mp3 player based on flash memory and iPod based on mobile hard disk.

Except for a few waveform files, most players have their own decoders to restore compressed media files, and players also have a set of frequency conversion and buffering algorithms.

In the past, the software for playing audio and video has its own characteristics, but now most of them are integrated audio and video players.

The quality of a player software can be measured from three aspects: kernel, interactive interface and playing mode.

Kernel mainly refers to many algorithms related to sound quality, such as decoding, buffering, frequency conversion and so on. The interactive interface mainly refers to the external interface for users to interact with software, and the playing mode mainly refers to how the player plays which songs to satisfy users' playing habits and psychology.

The importance of kernel, interactive interface and playback mode in player design decreases in turn. So that most players play very similar games.

In order to improve the extended functions and personalized interface, most players support third-party plug-ins.