## Definitions

Here is a list of terms used throughout this website and also in the help panels of the SuDoku Solver.

### Square

A single square in the SuDoku which may contain one of the numbers 1 to 9.

### Grid

The whole SuDoku, made up of 81 Squares arranged in a 9 x 9 grid.

Nine adjacent horizontal Squares in which the numbers 1 to 9 each occur only once.

Nine adjacent vertical Squares in which the numbers 1 to 9 each occur only once.

Nine Squares arranged in a 3 x 3 grid in which the numbers 1 to 9 each occur only once.
There are nine Boxes in the whole SuDoku Grid.

Three adjacent Squares arranged either horizontally or vertically that are all in the same Row and Box,
or in the same Column and Box.

In a correctly completed SuDoku, the Solution for each Square is the number in that Square.

The possible solutions for each Square. Initially, all the numbers 1 to 9 may be Possibles
in a particular Square until they are eliminated by the action of various Analyses. Eventually there is
only one Possible left and that becomes the Solution for that Square.

A Square which has only two remaining Possibles. The starting point for the Splits Analysis.

Two or more Squares in the same Row, Column, or Box that have the same Solution. Or a Square with no Solution
and no Possibles.

In a Killer SuDoku, a group of Squares whose Solutions add up to a known total. A Group is outlined with a
dashed-line boundary with the total in the top-left corner.