All gameplay in Warstorm is conducted through the use of cards. New players start with enough cards to have one Hero and can create one squad, and earn extra cards through winning single player battles, levelling up and completing Achievements.
Cards can be:
Cards can also refer to the Warstorm Card Viewer, which provides a convenient way to view all the cards in your collection. When you open it,you will see all the cards you have. A number below each card tells you how many copies you have of each card. There are a variety of filters allowing you to see different parts of your collection.
Furthermore, cards all have a card type and all follow the same card layout - more information can be found at those pages.