Klondike is the name of the game that most of us are familiar with and refer to as 'solitaire'. In Klondike there are 7 foundation piles with the top card face up. There is a stockpile where the player draws three cards at a time and may play only the top available card.
Below are some popular variations:
Yukon is a variation on this where there is no stockpile. Instead the remaining cards are laid down overlapping the 6 right most cards in the stockpile.
Bristol Fans has 8 foundation piles with the cards fanned out. There are three cards in reserve and a stockpile.