A container format, or wrapper format, is a metafile format whose specifications describe how different data elements and meta data are arranged. Although container formats are used for a variety of file types within and across operating systems, the most frequent way the average computer user interacts with container formats is via multimedia files.
Knowing the container format is helpful when working with multimedia files because it informs you of the constraints of that particular container format. For example, if you wanted to rip a movie and maintain a discrete channel within the container format for subtitles then Microsoft’s AVI format would be a poor choice–it only supports discrete subtitles via third-party tweaks. Selecting another format, such as Matroska (e.g. .MKV files) would allow you to freely add the discrete subtitles you desired.
It’s important to note that the container format is not the codec (the codec is a separate encoding/decoding algorithm that is usually specified in the container format but is not the container format itself).
- By Jason Fitzpatrick on 03/8/13