Each pile represents a different suit and should be filled in order, starting with the Ace all the way to the King. These are the four empty areas at the top of the game. To win, you want to place all the cards in the four foundation piles. When you hear the game Solitaire, in general it refers to Klondike Solitaire.
Klondike Solitaire refers to the classic version of solitaire. Use hints and undos, and customize your game experience.