A phrase is a group of words in a sentence that does NOT contain a subject and a verb. In other words, in a sentence, one part with subject and verb is a clause while the rest of it without those two parts of speeches is a phrase.
<u>Example:</u>
<em>On the wall, in the water, over the horizon.</em>
A clause is a group of words in a sentence which contains a subject and a verb.
A phrase is a group of words in a sentence that does not contain a subject and a verb. Such as saying a field. But clauses is a sentence that does contain a subject and a verb such as saying he is playing in a field