- a puzzle printed on a square grid of nine large squares each subdivided into nine smaller squares, the object of which is to fill in each of the 81 squares so that each column, row, and large square contains every number from 1 to 9.
- a type of puzzle in which numbers must be arranɡed within a ɡrid contaninɡ several internal squares so that no number is repeated in the same row, column, or internal square
