Completeness

A factor often brought up in collecting games is Completeness, this is mort notably in more Retro games that were in cardboard boxes, as people often threw these boxes away inboxed copies of games (or complete copies) are more expensive and hard to find, but something doesn't have 100% completeness unless it also has the manual, Disc, Cartridge, etc. and any other form of media the game was released with.

Factory Sealed
Main Article: "Factory Sealed"

While having a Factory Sealed product isn't needed for said products completeness, it's very similar, Factory Sealed means that a product is still in its plastic, or when it comes to certain other things (ex. Nintendo 64 Controller) haven't been opened.