Sliding Puzzle

A sliding puzzle, sliding block puzzle, or sliding tile puzzle is a tour puzzle that challenges a player to slide (frequently flat) pieces along certain routes (usually on a board) to establish a certain end-configuration. The pieces to be moved may consist of simple shapes, or they may be imprinted with colors, patterns, sections of a larger picture (like a jigsaw puzzle), numbers, or letters. You have to slide the tiles to reassemble a picture, by touching the block you want to move.