In this system information is stored on cards. Each card is of a specific card type. The type determines which fields (and thus what information) is stored on each card.
You can think of cards as the digital version of information cards in a physical filing cabinet, but now easy to search, relate and filter.
The different stacks of cards reside in a collection. This makes it easy to work together on specific sets of cards.
The fields determine what kind of information you can store on a card. In Use.cards you can determine exactly which fields are needed for your usecase, and if necessary later add or remove fields easily.