Puzzles/Rubik's cubes
Rubik's cubes
Rubik's cubes are permutation puzzles. The design was originally invented by Ernő Rubik. The cube has 6 colored faces and the goal is to get the same color on each face. The Rubik's cube (3x3x3) was the best selling toy of the 20th century.
A permutation puzzle is a puzzle that has to be solved by changing its configuration or position by interchanging elements. Usually there are several ways to get to the solution.