ALT tldr: Use Bottom Sheets as part of your layout, use Modal Bottom Sheet as a result of a user action (such try to delete something -> show modal with "are you sure you want to delete this? y/n") longer version: BottomSheet is used to build any bottom sheet of any design in your app. Bottom sheets are part of your screen's layout and can be either fixed/always-visible (such as "Now playing" mini players in music apps such as Spotify) or swiped away (such as the Google Maps bottom sheet) Modals (the ux pattern) are prompts that interupt the user from whatever they are doing and ask them to make a choise. Those are specific to a user action, not a screen (ie "you are about to delete this. are you 100% sure?"). Android's de-facto modal is the Dialog, and later on Modal Bottom Sheets were introduced. (dialogs are usually more compact, modal sheets are more ergonomical, closer to reach on touch).