A Karnaugh map (K-map) is a visual tool used in Boolean algebra to simplify logical expressions. It organizes truth values of variables in a grid format, allowing users to easily identify patterns and minimize complex logic functions. This method is particularly useful in designing digital circuits. Karnaugh maps can handle up to six variables, with each cell representing a specific combination of input values. By grouping adjacent cells that contain 1s, users can derive simpler expressions, reducing the number of gates needed in circuit design. This efficiency is crucial in optimizing electronic systems.