This is a glossary of Sudoku terms and jargon. Sudoku with a 9×9 grid is assumed, unless otherwise noted.

Terminology and grid layout

A Sudoku (i.e. the puzzle) is a partially completed grid. A grid has 9 rows, 9 columns and 9 boxes, each having 9 cells (81 total). Boxes can also be called blocks or regions. Three horizontally adjacent blocks are a band, and three vertically adjacent blocks are a stack. The initially defined values are clues or givens. An ordinary Sudoku (i.e. a proper Sudoku) has one solution. Rows, columns and regions can be collectively referred to as groups, of which the grid has 27. The One Rule encapsulates the three prime rules, i.e. each digit (or number) can occur only once in each row, column, and box; and can be compactly stated as: "Each digit appears once in each group."

Other terminology

[An automorphic Sudoku. (also displays dihedral symmetry),

(24 clues). | upload.wikimedia.org/wikipedia/commons/d/d3/Sudoku///Puzzle///%28a///puzzle///with///total///symmetry%29///trimmed.png]

Sudoku variants

The classic 9×9 Sudoku format can be generalized to an This accommodates variants by region size and shape, e.g. 6-cell rectangular regions. (N×N Sudoku is square). For prime N, polyomino-shaped regions can be used and the requirement to use equal-sized regions, or have the regions entirely cover the grid can be relaxed. Other variations include additional value placement constraints, alternate symbols (e.g. letters), alternate mechanism for expressing the clues, and compositions with overlapping grids. See Sudoku – Variants for details and additional variants.

[A Sudoku variant with prime N (7×7) and solution.

(with Japanese symbols). | upload.wikimedia.org/wikipedia/commons/d/d0/Didoku///Wave///puzzle///and///Solution///Happiness///for///everyone///%28Japanese%29///www.didoku.com///MiguelPalomo.png]

Sudoku types and classes

Variants by size

Variants with additional or different constraints

Sudokus variants can also have additional constraints on the placement of digits, such as "< >" relations, sums, linked cells, etc.

Terms related to solving

The meanings of most of these terms can be extended to region shapes other than boxes (square-shaped). To simplify reading, definitions are given only in terms of boxes.