Because i honestly dont know

I think that stone will be the only one to awnser this which is fine cus i pretty much just wanted to ask him but anyone who has an awnser is welcome to reply. i would like some kind of explanation as to what the difference between a caucuse and a primary is. ive been reading alot about the elections and what not to try and stay informed but i find myself at a disadvantage because i dont know whats these terms mean really. so if you can help awesome thanks. a link to a page explaining them would be awesome too. i just want to be more informed. thank you