Meta data contains information about a media item and is populated by the user or when the file is analyzed. Often the media itself contains a set of meta data that is stored in the file. Depending on the type of media item, different types of meta data can be contained in the file. IPTC, XMP and Exif are common meta data formats for images. RIFF for video and ID3 for audio files.
When the file is uploaded/imported to ImageVault, an analyzer analyzes the file and extracts the meta data and indexes it.