Solitaire or Patience are a family of solitaire games with a standard playing card deck. While most Patience rules are for 1 player, there are a few Patience game rules for 2 players! They are also called "Zankpatiencen" (quarrel patiences) in German Patience books.
There are also commercial versions available with a collection of 2 full card decks (including Jokers), especially made to play Patience. The cards are extra small to carry in your pocket, in a little box. Instructions for several different Solitaire games are included.
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.