Solitaire
A solitaire is any game which one can play by oneself, usually with cards, but also with dominoes. The term is also used for single-player games of concentration and skill using a set layout of tiles, pegs or stones. These games include peg solitaire and mahjong solitaire.  The term by definition describes a game played by one person, but these games can incorporate others.

Types of solitaire games
Patience or card solitaire, also known as "solitaire with cards", generally involves placing cards in a layout, and sorting them according to specific rules. The most common solitaire card game is Klondike. Other popular variations include Spider, Yukon, and FreeCell. The origins of Card Solitaire or Patience are unclear, but the earliest records appear in the late 1700s across northern Europe and Scandinavia. The term Patiencespiel appears in Das neue Königliche L’Hombre-Spiel, a German book published in 1788. Books were also reported to appear in Sweden and Russia in the early 1800s. There are additional references to Patience in French literature. The earliest collection of patience games in the English language is attributed to Lady Adelaide Cadogan who wrote Illustrated Games of Patience around 1870. In the United States, the first card solitaire book, Patience: A series of thirty games with cards, was published by Ednah Cheney in 1870.  Other important early works of the late 19th and early 20th centuries were by H. E. Jones (a.k.a. Cavendish), Angelo Lewis (a.k.a. Professor Hoffmann), Basil Dalton, Ernest Bergholt, and Mary Whitmore Jones. In the early 20th century the name "solitaire" became established in North America. The most popular card solitaire is Klondike, which was called Microsoft Solitaire in a digital implementation included with the Windows operating system from 1990 onwards.
Mahjong solitaire is a single-player matching game that uses a set of mahjong tiles rather than playing cards. It is more commonly played on a computer, than as a physical tabletop game.
Peg solitaire is a board game where the goal is to empty the board of pegs through movement and capturing.  It is more of a puzzle than a game, since it is repeatable once it is solved.

See also
List of patience games

Notes
References
Literature
Parlett, David (2008). The Penguin Book of Card Games. London: Penguin. ISBN 978-0-141-03787-5

External links
David Parlett. Historic Card Games: Patience playing-card solitaires