Quaternian rotations

I dont fucking get it

i get that rotating using quats involves x y z and w, where x y and z is a vector that defines an axis about which you rotate by w, but what is w in? its not degrees, and its not radians, and its not cos degress..... arg

What is the subject?

It its below the first level of calculus, you only use y, x, and z....But if its physics, then w can just be measuring x, y, and z against something like time...Radians and degrees are only ways to express the answer (since they can easily be converted)...so if x, y, and z are using either, so will w(unless your problem is just busy work to convert)