Phrases and clauses are the key building blocks of sentences. A clause contains a subject and a verb and can express a complete thought. A phrase does not contain a subject or verb.
The two types of clauses in English grammar are the independent and dependent clause. Both have a subject and verb which makes them clauses, but while independent clauses express a complete thought, dependent clauses do not. This is the main distinction.
Direct and indirect objects are key parts of most sentences. A direct object is the receiver of action while indirect object identifies to or for whom or what the action of the verb is performed.