Ok--I gotta ask because I think I have an impression of what I think it is but am not exactly sure.
Premium denim-- I think expensive soft denim looking cloth in a jeans pant, not made for tough wear. Form fitting cut/cloth. Multiple colours but mostly darker blues. Small pockets.
Regular denim (is this what you call it??)-- cheaper priced--stiffer canvas like cloth made for tougher wear or work. More generic cut-pant shape. Blue.

How far off am I LOL??