The answer would be that 1 is a sentence fragment and 2 is a sentence.
Explanation:
Sentence fragments are group of words that look like sentences but aren't. In order to be a sentence, group of words need to have at least one independent clause. An independent clause is a group of words that contain a subject and a verb and can stand alone as a sentence as they represent a complete thought. A sentence fragment, such as the one in 1, does not represent a complete thought. 1 does not contain a verb.
