Components that will allow you to organize your media library to help with the creation of channels that do things the way you want.
Filler lists are collections of videos that you may want to play during 'flex' time segments. Flex is time within a channel that does not have a program scheduled (Usually used for padding).
Custom Shows are sequences of videos that represent a episodes of a virtual TV show. When you add these shows to a channel, the schedule tools will treat the videos as if they belonged to a single TV show.