going from PC Photoshop CS6 2010 to Element for Mac and vice-versa?

My son is using Photoshop CS6 2010 on Windows at school. We have a Mac at home and need to install the program so he can do his homework. As the cost of "full photoshop" is huge, we would rather install Element. However, we would like to be sure that he can go from MAC to PC and Element to Photoshop without problems. Thank in advance for your advices.