The AVI (Audio Video Interleave) video format is a multimedia container developed by Microsoft that can contain both audio and video data. AVI files use various video and audio codecs to encode the content, providing flexibility in terms of compression and quality. While once a popular format for storing video on Windows platforms, AVI has been largely superseded by more modern and efficient video formats like MP4. Nonetheless, AVI files are still compatible with many media players and editing software, making them accessible for playback and editing purposes.