In 2017 Apple launched the iPhone X. (It’s pronounced iPhone ten apparently). The biggest change to iPhones since they first came out, becaus there wasn’t any Home Button. Then in 2018 they released 3 new iPhones. The iPhone XS, the XS Max and the XR. None of these have Home Buttons either.
With older iPhones you just pressed the Home Button to get back to the main screen when you were finished with an App. On the new iPhones you need to swipe up from the bottom of the screen.