Software on an end-user's computer that decodes and decompresses audio or video streaming content, e.g., Real Player, Windows Media Player and Apple Quick Time.
An application used to display an sound, video or unique file format. When built into a browser, a Player is a Plug-In. For example, Quicktime, Real Audio and Adobe Acrobat. When run as an application outside of a browser the software is usually called a Player.