To boil is a cooking method where a liquid (usually water) is heated until many bubbles appear on the surface. A rapid boil is when the bubbles appear very quickly.
For water to reach its boiling point, it has to reach 100 °C or 211.9 °F.
Always be careful when boiling liquid, as the hot substance can splatter up against you. The steam from the boiling liquid can be hazardous as it can also burn you.
We have given a video below that demonstrates the difference between simmering and boiling water.
Learn the difference between simmering and boiling:
CLICK ON IMAGE TO PLAY