Floating action buttons (FABs) were originally popularized by Google’s Material Design guidelines.^[1] They provide consistent and fixed primary buttons. In general, they’re circular or square with rounded corners, icon-only, raised buttons fixed to the edge or corner of the screen. You’ve probably seen them in Google’s apps, like in the case of the plus-sign Add Event button in Google Calendar.

You should use only one FAB per page for constructive primary actions like creating, adding, or sharing.