Sudoku is a logic based puzzle game. This game was originally being known as Number Place game. This game has a 9×9 grid of places where digits are to be filled based on existing digits and logic. Each small square is known as cells. This game has 9 rows and 9 columns which can have number 1 to 9 in each row and column without any repetition. The grid is divided into sub grid of 3×3 that is also called regions (or box or block). This 3×3 sub grid can have number 1 to 9 without any repetition. This is explained in the picture given below.