Toast is usually buttered, but it's not considered to be a sandwich in and of itself in the United States.
Now, a sandwich can be made with toasted bread, certainly, but in that role it's normally slathered with mayonnaise, mustard, or something of that nature rather than being buttered.
Exception: grilled cheese sandwiches are often buttered, though with those they typically have the butter on the outside. On the inside is either nothing or (my preference) mayonnaise.
Now, a sandwich can be made with toasted bread, certainly, but in that role it's normally slathered with mayonnaise, mustard, or something of that nature rather than being buttered.
Exception: grilled cheese sandwiches are often buttered, though with those they typically have the butter on the outside. On the inside is either nothing or (my preference) mayonnaise.