If the person leaves their finger longer than 370 milliseconds before removing it, onLongPress is triggered. (onPressOut will still fire when they remove their finger.)
Fingers are not the most precise instruments, and it is common for users to accidentally activate the wrong element or miss the activation area. To help, Pressable has an optional HitRect you can use to define how far a touch can register away from the the wrapped element. Presses can start anywhere within a HitRect.
PressRect allows presses to move beyond the element and its HitRect while maintaining activation and being eligible for a "press"—think of sliding your finger slowly away from a button you're pressing down on.
The touch area never extends past the parent view bounds and the Z-index of sibling views always takes precedence if a touch hits two overlapping views.
Pressable uses React Native's Pressability API. For more information around the state machine flow of Pressability and how it works, check out the implementation for Pressability.