As part of this standard VFW defined the well known AVI (Audi Video Interleaved), which is able to store audio as well as videostreams in one file. An interface for codecs (somekind of videodrivers) was also implemented into vfw. These codecs describe how a video file is compressed, and recompressed during playback.
The best known producers for codecs are Cinepak and Intel Indeo.