Perhaps class system is a better term. The terms nearly mean the same thing but not quite. I think the caste system is closer in origin to the societal structure in
the feudal system that was common in medieval Europe, than the modern class system.
Class specifically can be changed, whereas caste cannot. You can dress better, pronounce words in an upper class style, and live in a better neighborhood but still be treated like you need to use the back door to enter your own office because of the color of your skin.
