The system navigation introduced in Android 9 Pie, sometimes referred to as gesture navigation, is facilitated by a component called Quickstep. This component governs the visual and interactive elements that allow users to switch between applications, return to the home screen, and access the overview screen (also known as the recent apps list) through swiping gestures rather than traditional on-screen buttons. As an example, swiping up from the bottom of the screen typically navigates to the home screen, while swiping up and holding displays the overview screen.
The adoption of gesture navigation through Quickstep aims to provide a more immersive and efficient user experience. By eliminating the persistent navigation bar, screen real estate is maximized, allowing for increased content visibility. Furthermore, the fluid gestures offer a potentially faster and more intuitive method of navigating the operating system compared to the conventional three-button navigation system. The historical context involves a broader industry trend towards gesture-based interfaces, seeking to emulate the ease of use seen on devices like the iPhone.