Your phone runs android. But to separate all the android phones from looking the same, the companies customize the look and features of android. Samsung does this with their own phones. And it was called 'Touchwiz UX'. After the S8 was released, they made the software smoother and better. They called it 'Experience UX'. Now with the release of S10, they made the software much smoother and better looking and made using the phone with ONE hand easier. This is called One UI. Check out more : https://www.samsung.com/global/galaxy/apps/one-ui/
