A clause is similar to a sentence because both clauses and sentences have subjects and verbs.
Sentences are made of clauses.
A simple sentence contains one clause.
Compound and complex sentences contain more than one clause.
Differences:
Both clause and sentence are made up of a group of words that contain a subject and a predicate. The main difference between clause and sentence is that a sentence always conveys an independent meaning whereas a clause does not always convey an independent meaning