Does every single detail of your world need to be unique? No. Your genre will determine some of the basic framework. It’s ok to rely on some conventions—otherwise your reader might get completely lost. For example, if you're writing a science fiction scene about a battle in space, you can use some common terms to describe parts of the ships (wing, hull, cockpit, shields) and the players (generals, soldiers, medics, officers). But be sure to work in some key, unique details to make your world stand out from others in the genre. In the sci-fi example, it could be some special weapon, the colorful logos on the sides of the ships, or the piloting interface inside the ship. It’s your overall take that needs to be original, not each and every piece.