Collections can be thought of as visual media playlists. A Saved Search collection allows you to automatically ingest content using pre-set filters you select, whereas Manual collections are completely editorial. Click here to learn more about Collections.
Channels can be thought of as folders in which to organize content according to language, content type, stations, etc. Similar to a folder, media can only exist in channel at a time. Learn more about channels here.
Groups are used to organize media and members into flexible, customized containers. They are searchable, support custom meta-data and can be manually ordered for display. Unlike channels, media and members can be placed in multiple groups. Click here to learn about setting up groups.
All three of these objects can be used to filter calls to the Media Factory API.