I think you meant the difference between "going to" and "want to"? Well, it's really simple "Going to" defies your future plans you have already made arrangements for, like, "I'm going to eat a chocolate bar, here it is, in my hand". Or. "You're going to be late, you've missed the bus". GT shows you are certain that sth. is going to happen in the future. And "want to" is a mere thought. Like, "I want to talk to you" ( I'm not sure if the talk will actually happen, but I display my willingness to have a chat). Or. "I want to be a star when I grow up" (You don't know if you will succeed, but it doesn't stop you from wanting it). I hope this helps ;)

Will displays future tense. Want displays desire to have-do something

now what the difference between"want" and "will"?