Is there a distinction between censorship and a subset of books approved as curriculum? To me (not from the US, far from conservative), it seems needlessly div

Is there a distinction between censorship and a subset of books approved as curriculum? To me (not from the US, far from conservative), it seems needlessly divisive. I'm all for real-world examples in maths/science instruction, but there'd surely be better alternatives that keep focus on learning the core topic at hand.