A K-Map, or Karnaugh Map, is a visual tool used in Boolean algebra to simplify logical expressions. It organizes truth values in a grid format, allowing users to easily identify patterns and minimize the number of terms in a logical equation. This simplification helps in designing efficient digital circuits. K-Maps are particularly useful for functions with up to six variables, as they provide a straightforward method for grouping ones in the map. By combining adjacent cells, users can derive simpler expressions, which can lead to reduced complexity in circuit design and improved performance in digital systems.