A digital file format that holds audio, video and subtitles. Containers support a variety of audio and video compression methods and are not tied to one particular audio or video codec. AVI was the first Windows container format, and Matroska/MKV is a popular open source container. MPEG-4, QuickTime and RealMedia are also A/V containers. See
codec examples.
Multimedia Container Examples
Microsoft AVI
Apple QuickTime
Streaming RealMedia
Open Source Matroska
MPEG-4 MP4