Karnaugh map
The Karnaugh map (Kmap) is a matrix that represent output values of a boolean function. It is primarily used to reduce digital circuits.
Minterm
A minterm is a term that consists of all inputs, complemented or not.
Matrix
Kmap minimize equations graphically. Each cell represent an input. There cannot be more than one bit change from one column to the next.
If there are more variables, multiple is placed for an axis. Note the restriction regarding bit change means that conventional order of inputs is invalid.
Simplify
Circle 1's in adjacent squares. Every grouping represents a term. A grouping has to be a power of 2 and be as large as possible.
Don't-cares can be included or excluded depending on whether it minimizes the equation.
How it works
Adjacent columns/rows have one bit difference. If two 1's are adjacent, it means that that particular one bit difference does not matter. A simplification is then found.