What is the name of the game where you have to move mixed squares of an image to get it right again?

Question

It has one empty slot so that you can move the squares through it, and when you're done you are left with the image that has that empty slot in one of the corners.

Thanks in advance for the answers.

Answer 1

Does it have a name?

Answer 2

it is called the 15 puzzle

Answer 3

the missing piece puzzle....lol, tht's the best i can do