There are coordinating conjunctions and there are subordinating conjunctions. Coordinating conjunctions include 'for,' 'nor,' 'but,' 'or,' and other words. Coordinating conjunctions join two equal parts of speech. They can connect words to words, phrase to phrases, and clauses to clauses.
Subordinating conjunctions come at the beginning of a clause. It makes a dependent clause depend on an independent clause to make the sentence understandable. Some subordinating conjunctions are 'because,' 'while,' 'than,' and 'as.'