The Star Wars was a conflict between the Human Imperium and a rogue faction from 14 BBY to 7 BBY. The Human Imperium was comprised of mostly Humans, select Near Humans/Humanoids and droids, while the rogue faction constituted aliens of all kind, from Twi'lek, to Verpine and other less than human beings.
Behind the scenes
The war was informally called the Star Wars in universe. The name was inspired by The Great War (World War I), because many films utilize "the" in reference to the war. Likewise, the Star Wars was an homage to the title of George Lucas' initial Star Wars film; now known as Star Wars Episode IV: A New Hope.