Solitaire (or Patience as it is called outside the US and Canada) is a general term for many popular single player card games. Klondike is the most common type of Solitaire, and the goal of the game is to move the cards in such a way that you end with four stacks, one of each suit, of all the cards of that suit (starting with Aces). Most Windows computers come with a free solitaire game packed in, which is another reason for its popularity.