Solitaire (Card Game)
A family of single-player card games of a generally similar character, but varying greatly in detail. (The term "Patience" is more commonly used in British English.) These games typically involve dealing cards from a shuffled decked into a prescribed arrangement on a tabletop, from which the player attempts to reorder the deck by suit and rank through a series of moves transferring cards from one place to another under prescribed restrictions. There are many different solitaire games, but the term "Solitaire" is often used to refer specifically to the most well-known form of the game, properly called "Klondike".
Solitaire (Peg Game)
Solitaire is also a game for one player, usually using pegs in holes. The board is in the following shape:
OOO OOO OOO OOOOOOOOO OOOOOOOOO OOOOOOOOO OOO OOO OOO
with a peg in each hole, except for the centre piece. Moves are made by jumping a piece over another piece, either horizontally or vertically into an empty hole, and the piece that was jumped over is removed from the board and the game. The piece that moved may move again in the same fashion.
The aim of the game is, ideally, to end up with a single piece in the centre hole in as few moves as possible, but ending up with only one piece left over, let alone in the middle, is still extremely challenging, and leaving a small number of pieces on the board is considered good going.