Can anyone explain what the hell boolean calculus is? How do you differentiate something that's all discrete like that? What's the point?

In a boolean function your variables would be like y = 4>3 and x = 10>4 and the constants can only be 1 or 0? y = x = 1 in this scenario? Or is that backwards?

My brother's going on about boolean this and boolean that after his comp sci class today and between differentials and weird symbols it's making my brain hurt