# Confusion about $\ dW_t^2$ and $\ dt^2$

I start learning stochastic calculus and always come across this 2 notations $$\ dW_t^2 , dt^2$$

Does $$\ dW_t^2$$ mean $$\ d(W_t)^2$$ or $$\ (dW_t)^2$$ ?

Similarly, does $$\ dt^2$$ means $$\ d(t^2)$$ or $$\ (dt)^2$$?

Thanks.