Floating action button is used for a special type of promoted action,it animates onto the screen as an expanding piece of material, by default. The icon within it may be animated,also FAB may move differently than other UI elements because of their relative importance. A floating action button represents the primary action in an application which can simply trigger an action or navigate somewhere.
Floating-point numbers are numbers that have fractional parts (usually expressed with a decimal point). In Java, there is two primitive types for floating-point numbers which are
float (uses 4 bytes), and
double (uses 8 bytes). This documentation page is for detailing with examples operations that can be done on floating points in Java.