Customization. You hear that word a lot when reading things about Jeep Wranglers. New bumpers this, or lift kits that. Tops, lights, rock rails. And yet, while all those products are nice, swapping up your JL's wheels does so much more than just provide a nice visual change.
Like the JK series before it, your JL Wrangler's wheels come in a 5x5 bolt pattern which means that there are plenty of good choices, right now, that are available in either steel or aluminum. Not sure what size wheel you have? Well if you are a JL Sport or Rubicon owner, you have 17" wheels, while Sahara owners have 18" rims. Then there is material choice. Steel is heavier, more durable, and is generally the choice for the serious off-road crowd. Steel rims can take a pounding and, if something happens on the trail, can be hammered back into shape. Alloy rims are lighter, give you increased fuel economy, and handle better so daily drivers usually choose these. They are also, normally, less expensive than steel so if they do take a trail beating, they can be replaced without much expense.
Besides material construction, wheels also offer different backspacing and offset variables. Generally speaking, the lower those offset and backspace numbers, the further out the wheel will mount which certainly helps if your modification plans include a lift kit and larger tires.