Sudoku is a logic-based, combinatorial number-placement puzzle. The puzzle setter provides a partially completed grid, which for a well-posed puzzle has a single solution. wikipedia.org
In classic Sudoku, the objective is to fill a 9 × 9 grid with digits so that each column, each row, and each of the nine 3 × 3 subgrids that compose the grid (also called "boxes", "blocks", or "regions") contain all of the digits from 1 to 9.
The modern Sudoku was most likely designed anonymously by Howard Garns a 74-year-old retired architect and freelance puzzle constructor from Connersville, Indiana, and first published in 1979 by Dell Magazines as Number Place (the earliest known examples of modern Sudoku).