Dependent clause is a group of words that contains a subject and a predicate. Although this contains a subject and a predicate, the thought is not complete and can not stand on its own. For example, "since he did not pay the rent". In this instance, the clause has a subject and a verb but shows no thought or meaning.
An independent clause is a group of words comprised of a subject and a predicate and expresses a thought thus, called independent. For instance, "I arrived early", "She sings."