Not every RAM stick is compatible with every brand of motherboard, there are mainly 3 types of RAM that you will find DDR, DDR2, DDR3. But usally at this point of time, you will mostly see DDR3 RAM for sale but not so much DDR2 and DDR. Almost every modern motherboard you find for sale at this moment would be supporting DDR3 RAM, so if you are looking for a new build the chances are, your RAM is going to be DDR3 and your motherboard is going to support it, unless you are looking to upgrade.
Hope I helped