Puzzles are problems intentionally designed to stimulate the brain into devising solutions. Puzzles can be differentiated from games as the latter are aimed primarily at entertainment, although games like chess, checkers, and solitaire are made up of many puzzles.

Puzzles are broadly categorized into riddles and word plays, logic and mathematical puzzles, and physical puzzles. Some of the popular riddles are conundrums, charades, crosswords, and anagrams. Paradoxes and magic squares are two of the popular mathematical puzzles, which include a wide array of puzzles including geometric puzzles, decision puzzles, number sequences, action sequences, analytical puzzles, and logic puzzles. Jigsaws, labyrinths, and mazes are some of the examples of physical and mechanical puzzles.

Puzzles have been ingrained into the human culture since the very beginning. One of the oldest and most popular puzzles is Tangram, which has been teasing minds all over the world for thousands of year. Humans have been known to devise oral puzzles since the advent of languages. Riddles have been integral part of ancient scriptures and religious literature, including the Koran, Bible, Sanskrit scriptures, and Greek mythology.

The development of arithmetic in Egypt resulted in birth of mathematical puzzles. The interest in mathematical puzzles grew from the fifth century to the fifteenth century. The popular mechanical puzzle labyrinth was incorporated in the floor designs of many churches in France and Italy in the twelfth century. Sam Loyd of the United States and Henry Dudeney from Britain are considered greatest puzzle inventors in their countries. The duo devised numerous puzzles in nineteenth century.

The extent to which puzzles have become part of daily life can be gauged from the popularity of crosswords, jigsaw puzzles, and Sudoku.