Sudoku is a logic-based, combinatorial[ number-placement puzzle. The objective is to fill a 99 grid with digits so that each column, each row, and each of the nine 33 sub-grids that compose the grid (also called "boxes", "blocks", "regions", or "sub-squares") contains all of the digits from 1 to 9. The puzzle setter provides a partially completed grid. Completed puzzles are always a type of Latin square with an additional constraint on the contents of individual regions.

Sudoku was popularized in 1986 by the Japanese puzzle company Nikoli, under the name Sudoku, meaning single number It became an international hit in 2005

Number puzzles first appeared in newspapers in the late 19th century, when French puzzle setters began experimenting with removing numbers from magic squares. Le Sicle, a Paris-based daily, published a partially completed 99 magic square with 33 sub-squares on November 19, 1892. It was not a Sudoku because it contained double-digit numbers and required arithmetic rather than logic to solve, but it shared key characteristics: each row, column and sub-square added up to the same number.
From La France newspaper, July 6, 1895.On July 6, 1895, Le Sicle's rival, La France, refined the puzzle so that it was almost a modern Sudoku. It simplified the 99 magic square puzzle so that each row, column and broken diagonals contained only the numbers 19, but did not mark the sub-squares. Although they are unmarked, each 33 sub-square does indeed comprise the numbers 19 and the additional constraint on the broken diagonals leads to only one solution.
These weekly puzzles were a feature of French ne ...more

According to Will Shortz, the modern Sudoku was most likely designed anonymously by Howard Garns, a 74-year-old retired architect and freelance puzzle constructor from Indiana, and first published in 1979 by Dell Magazines as Number Place (the earliest known examples of modern Sudoku). The puzzle was introduced in Japan by Nikoli in the paper Monthly Nikolist in April 1984 as Suuji (or suji) wa dokushin ni kagiru which can be translated as "the digits must be single" or "the digits are limited to one occurrence." At a later date, the name was abbreviated to Sudoku by Maki Kaji ,taking only the first kanji of compound words to form a shorter version.
source wikipedia