A typhoon is a tropical cyclone occurring in the northwestern Pacific Ocean.
“Tropical cyclone” is the general scientific term for a rotating low-pressure storm that forms over warm tropical or subtropical water. Regional names vary: the same type of storm is usually called a hurricane in the North Atlantic and northeastern Pacific, and a cyclone in much of the Indian Ocean and South Pacific.
The northwestern Pacific is the most active tropical-cyclone basin in the world. Typhoons can bring destructive winds, torrential rain, storm surges and flooding. Their strength depends on factors including ocean heat, atmospheric moisture and wind shear.
A typhoon is not a separate physical category from a hurricane. The different names primarily reflect regional usage. In the Philippines, some agencies also use local warning terminology, but international meteorological communication commonly uses “typhoon” for storms in this basin.