When you use the word custom that means something that can be customized by you according to your preferences and requirements. Similarly, custom PS4 controllers are customizable gamepads that can also be designed according to your preferences. The whole outlook of the controller and even the placements of buttons can be designed according to your choice.
This is a new development in the gaming world as now gamers can get their customized controllers and they don't have to rely on setting their hands-on stock gaming controllers. Build a custom PS4 controllers from MegaMods now to design and customize a controller at a reasonable price.