A phrase is a small group of words that adds meaning to a word. A phrase is not a sentence because it is not a complete idea with a subject and a predicate and thus, doesn't make sense completely.
Explanation:
A phrase is a group of words missing a subject and a verb. Therefore, it cannot be a complete sentence.
For example: The sun rises in the east.(In this sentence, in the east is the group of words which makes sense but not a complete sense, is called a phrase)
