What is Sudoku? - Sudoku (japanese 数独: sūdoku) is logical puzzle where goal is to fill a 9×9 grid with numbers so that each row, column and 3×3 section, contain all of the digits between 1 and 9. At the beginning, the 9×9 grid will have some of the squares filled in. Your job is to use logic to fill in the missing digits and complete the grid. For solving the puzzle you need some logical thinking, concentration and patience and with harder puzzles also some combinatorics, experimentation and returning.

History - Game is coming from Japan, where people play it for more then 1000 years. 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). Garns's name was always present on the list of contributors in issues of Dell Pencil Puzzles and Word Games that included Number Place, and was always absent from issues that did not. He died in 1989 before getting a chance to see his creation as a worldwide phenomenon.

Source: Wikipedia