Regions are also called "blocks" or "boxes". A "band" is a part of the grid that encapsulates 3 rows and 3 boxes, and a "stack" is a part of the grid that encapsulates 3 columns and 3 boxes. A "puzzle" is a partially completed "grid", and the initial values are "givens" or "clues". A "proper" puzzle has a unique solution. A "minimal" puzzle is a proper puzzle from which no clue can be removed without introducing additional solutions. See Glossary of Sudoku for other terminology.