The idea is to remove all the balls after the other by jumping over a ball into the empty space and removing them one by one. The game is called solitaire as you play it alone. Can you do it? There is only one way to the final solution and I know it, at least I did, but have forgotten in the meanwhile. You are sacrificing the balls constantly, but if you are clever, you have the advantage of clearing the board.
Usually they are little plastic toys, but this one has a solid wooden base with real marbles and was a gift we were once given on a visit to Marrakesh in Morocco.