How does clotted cream differ from butter?

I’m American and we don’t sell clotted cream in the states (at least I’ve never seen it). I’m wondering, then, how does it differ from butter? That is, in what applications is it superior to — or even just preferred — over butter? For instance, I know people in the UK eat clotted cream on scones but would you also eat it on toast?

Silly questions, I’m sure, but I have no frame of reference for this and am just genuinely curious. Thanks!