Synonyms: floating button, fab, primary button, primary action, main button
The floating action button is used either for primary action on the page or additional action. Another function of FBA is to turn one UI element to another or to reveal more options.
It appears onto the highest layer of the interface, in front of all other elements, and follows the user’s scrolls, remaining over his or her eyes. It is traditionally small-sized and round-shaped.
«don't really float my boat»
And because of the bold visual style of Material Design, FABs are strikingly hard to ignore and stand out — and herein lies the problem. While FABs seem to provide good UX in ideal conditions, in actual practice, widespread adoption of FABs might be detrimental to the overall UX of the app.