What is a Karnaugh map and how is it used for logic simplification?

A Karnaugh map (K-map) is a graphical method for simplifying Boolean expressions. It arranges truth table values in a grid where adjacent cells differ by only one variable (Gray code ordering). Groups of adjacent 1s (or 0s for POS) that are powers of 2 in size are circled, and each group yields a simplified product term. K-maps are practical for 2-4 variables, with 5-6 variable maps being more complex. For larger functions, Quine-McCluskey or computer algorithms are used.