A Sudoku solver is a tool or program designed to help users find solutions to Sudoku puzzles. These puzzles consist of a 9x9 grid divided into nine 3x3 subgrids, where the objective is to fill in the empty cells with numbers from 1 to 9. Each number must appear only once in each row, column, and subgrid. Sudoku solvers can be manual, where users apply logical techniques to deduce the correct numbers, or automated, using algorithms to compute solutions quickly. Many online platforms and mobile applications offer Sudoku solvers, making it easier for players to solve challenging puzzles or check their answers.