WMP (Windows Media Player) is Microsoft's offering for media playback. WMP is able to acquire (download) codecs as needed, and plays back most Audio & Video sources. The software is flexible and has all the features you would expect from a large company offering with very little limitations in its functionality. WMP also works with online music stores, to allow purchasing of music with DRM through the players interface. Last but not least is the ability to work with Portable Media Hardware (MP3 Players, etc.) by transferring and updating though a standard interface.