A dream is something you'd live to attain but know it might be realistic , but it keeps you focused. A goal is something that you work toward to attain. Like your goal is to spend a week in Hawaii; do you save the money, set aside vacation days, but the tickets, reserve the hotel room.
My dream is to go to UCLA college, get a degree in marine biology, and test my own, independent compositions to cure cancer. My goal is to get in ;) Another dream of mine is to find true love, but that probably isn't going to happen, haha :(