K-Lite Codec Pack Mega is the complete pack. It additionally GraphStudioNext, and a few extra DirectShow filters. K-Lite Codec Pack Full has some extras compared to the standard variant.
This pack is recommended for the average user.
It includes Media Player Classic, which is an excellent player for video files. K-Lite Codec Pack Standard contains a few additional features compared to the basic variant. This pack is for those who like a small, no-nonsense pack. K-Lite Codec Pack Basic contains everything you need to play all the common video file formats. There are four variants of the K-Lite Codec Pack: It also provides additional functionality such a thumbnail generation in Explorer. It contains everything you need to play all common audio and video file formats. K-Lite Mega Codec Pack is designed as a user-friendly solution for playing all your movie files. Basic, Standard, Full, Mega as well as the latest update. K-Lite Codec Pack is a free collection of components needed for audio and video playback in DirectShow players such as Windows Media Player, Media Center, and Media Player Classic.