Hurricanes, typhoons and tropical cyclones all refer to storms in which the winds reach more than 74 miles per hour. The difference in the names refers to the location where the storm originates. A hurricane is confined to the North Atlantic Ocean and the Northeast Pacific Ocean. A typhoon originates in the Northwest Pacific Ocean, and a cyclone occurs in the Indian Ocean, states the Hurricane Research Division of NOAA.
For a cyclone, there are further classifications based on location. A tropical cyclone is a storm of sufficient magnitude in the Southwest Indian Ocean. As a cyclone becomes more severe, it moves toward the Southeast Indian Ocean and is called a severe tropical cyclone, states National Geographic.
These storms all are caused by pressure differentials in the boundary between the atmosphere and ocean. Water is always evaporating from the ocean's surface because of sunlight. Once the water vapor rises and condenses into clouds and rainfall, it releases the energy that has the potential to power a storm. If there is low pressure over the ocean as the heat of the condensation is released, the conditions are ripe for a hurricane, and the heat powers the movement of the surrounding winds. The speed of these winds determines the strength of the tropical storm.