The term Rubik's Puzzle is a reference to the Rubik's CUBE, a 3-D mechanical puzzle invented in 1974 by Hungarian sculptor and professor of architecture Ernő Rubik. The CUBE consists of six faces, each of which is covered by nine stickers, among six solid colors. The goal of the puzzle is to rotate the pieces so that each face of the CUBE has one solid color. The solution to the puzzle is to arrange the colored squares of each face into a single color. The four-letter word for this puzzle is 'CUBE'.