There are two major types of clauses: Independent and dependent.
One way to differentiate the two types is to understand that dependent clauses always supply information to an independent clause. That is, they function as modifiers. Another way is to understand that dependent clauses begin with a word (sometimes two words) that links them to an independent clause. A clause that begins with one of these words cannot function as a sentence. Only independent clauses can function as sentences. Listed in the following table are some of these words: because, if, as, until, since, whereas, although, though, while.