At Google IO today, the search giant has detailed more aspects of Android P, the upcoming release that got its first developer preview in March and should be finalized in late summer. New gesture-based navigation Perhaps the most obvious new feature in Android P will be the new navigation system. This employs a pill-shaped Home button, and an on-demand Back button which doesn't show up on the home screen, for example. Swipe up from the pill and you'll enter Overview mode, with your apps scrolling horizontally this time around, and a set of predicted apps at the bottom. Swipe up again...
Source: https://www.gsmarena.com/android_p_beta_is_out_today_for_pixels-news-30932.php