What on Earth does all that paperwork mean? I get those questions all the time, especially about the different types of loans that there are.
Specifically, what is a fixed rate loan? Simply put, a fixed rate loan is a loan that no matter how long you have to pay on it, the interest rate that you're paying never change.
So there are loans out there that do move around. But for a fixed rate loan, whatever you're told your interest rate will be is what it's going to be until you have the whole thing paid off.

