Technically, the first is a monomial, because the parentheses make it a single "term"; the second is a binomial.
But to some extent, what to call it depends on the reason for asking. There are some procedures applicable to binomials that can be applied to either, because they depend not on how it happens to be written at the moment, but on its meaning. The two expressions mean exactly the same thing!
So, what is the context of your question?