A media container format (or sometimes referred to as wrapper format) is a format that can contain various types of data such as audio and video data. The data is compressed using a codec.
A codec (a compound of coder and decoder) is an algorithm used to compress and/or decompress a multimedia data stream in order to reduce the number of bytes needed to store or send.
Some container formats are limited to audio, like WAV files for Windows, AIFF for Mac and XMF; some are limited to still images such as FITS and TIFF. There are also containers that are flexible; it can hold several types of audio, video and other media such as ASF files for Windows, MP4, and Matroska. The most common multimedia containers are:
- 3GP – used by mobile phones
- ASF – standard WMA and WMV container
- AVI – standard Windows container
- Matroska – open standard