K-Lite Codec Pack is a collection of audio

Audio file format

An audio file format is a file format for storing digital audio data on a computer system. This data can be stored uncompressed, or compressed to reduce the file size. It can be a raw bitstream, but it is usually a container format or an audio data format with defined storage layer.-Types of...

 and video

Video

Video is the technology of electronically capturing, recording, processing, storing, transmitting, and reconstructing a sequence of still images representing scenes in motion.- History :...

 components for Microsoft Windows

Microsoft Windows

Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

 that enables the operating system

Operating system

An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...

 and its software to play back various audio and video formats generally not supported by the operating system itself. K-Lite Codec Pack also includes several related tools, including Media Player Classic

Media Player Classic

Media Player Classic is a compact media player for 32-bit and 64-bit Microsoft Windows. The application mimics the look and feel of the old, lightweight Windows Media Player 6.4 but integrates most options and features found in modern media players...

, GSpot Codec Information Appliance

GSpot

GSpot is a Windows-based freeware designed to identify codecs used in video files. In addition, the application checks if the required DirectShow filters or Video for Windows codecs are installed and configured for proper playback...

, and Codec Tweak Tool.
There are five editions of K-Lite Codec Pack, all being available free of charge.

1. Basic: The Basic edition is the smallest version and enables a Microsoft Windows computer to play Matroska (MKV)
   Matroska
   The Matroska Multimedia Container is an open standard free container format, a file format that can hold an unlimited number of video, audio, picture or subtitle tracks in one file. It is intended to serve as a universal format for storing common multimedia content, like movies or TV shows...
   
   , MP4, Ogg
   Ogg
   Ogg is a free, open container format maintained by the Xiph.Org Foundation. The creators of the Ogg format state that it is unrestricted by software patents and is designed to provide for efficient streaming and manipulation of high quality digital multimedia.The Ogg container format can multiplex...
   
    and Adobe Flash video (FLV) files, in addition to various types of AVI
   Audio Video Interleave
   Audio Video Interleave , known by its acronym AVI, is a multimedia container format introduced by Microsoft in November 1992 as part of its Video for Windows technology. AVI files can contain both audio and video data in a file container that allows synchronous audio-with-video playback...
   
    files.