Answer:

A clause is a group of words having a subject and a verb of its own, but it forms part of a sentence. A clause has no independent existence.

In other words, a clause is a single sentence within a larger sentence, made of two or more than two clauses which are joined by suitable conjunctions.

Study the following sentences:

A morning walk is useful.

He saw the beggar and gave him a coin.

This is the girl who won the first prize.

Sentence No. 1 has already one finite verb and hence one clause. Sentence no. 2 has two clauses joined by ‘and’.