True-this can be tricky...if something has a high concentration, that means there are lots of substances floating around. however, there is less water. think about gatorade. if you add a bunch of water to it then it becomes diluted aka less concentrated. if you were to add extra salt and sugar to it, then it would be more concentrated. so if something is more concentrated, then there is less water. so water is going to move to areas that have a high concentration because there is less water on that side and its trying to reach equilibirum.