Hurricanes are powerful storms that grow in size over tropical seas. Sometimes these storms lose their power before they reach land, but when they do not they can kill large numbers of people and cause widespread property damage.
Hurricane, typhoon and cyclone are regional names for the same type of storm. Weather experts call them tropical cyclones.
The most deadly tropical cyclone in recorded history is thought to have been the Bangladesh cyclone of 1970, according to the United States Atlantic Oceanographic and Meteorological Laboratory. At least 300,000 people are thought to have perished.
Use the BBC News animated hurricane guide to see how hurricanes form.