Prolog has unification, which is considerably more powerful than just pattern matching. The semantics of Prolog require the ability to unify data structures with some parts not-yet-specified, and backtrack later if they cannot be bound to something valid. In contrast, pattern matching happens all at once and is unidirectional. (Though even basic pattern matching is tremendously useful, IMHO.)

Erlang's pattern matching is somewhat like Prolog's, but with backtracking removed. (Backtracking clashes with Erlang's other semantics.)