A cyclone is a large-scale air mass that rotates around a center of low atmospheric pressure. It forms over warm ocean waters when the heat from the water causes the air above it to warm up, become less dense, and rise. As this warm air rises, it creates a vacuum that draws in cooler air from surrounding areas. This process continues, leading to the development of a rotating system of winds. Cyclones can vary in intensity and size, and they are typically classified into different categories based on their wind speeds and potential for damage.