A conjunction is the glue that holds words, phrases and clauses (both dependent and independent ) together. There are three different kinds of conjunctions - coordinating, subordinating, and correlative - each serving its own, distinct purpose, but all working to bring words together.
Thanks to conjunctions, we don't have to write short, choppy sentences. We can extend our lines with simple words like "and" or "but" and perhaps a common or two.
Coordinating conjuction are what come to most people's minds when they hear the word "conjunction." They join together words, phrases, and independent clauses. With them, short and choppy sentences can be joined into fuller lines. There are seven of them, and they're easy to remember if you can just think of the acromyn "FANBOYS."