Neither. It is a phase in the warming and cooling of the Pacific, Indian and Atlantic oceans.
El Nino
el nino
el nino
It doesn't. El Nino has impacts all around the world. The ultimate trigger, though relates to the reversal of a wind current over the equatorial Pacific, which produces the characteristic warming of the surface waters. A few other patterns similar to El Nino have been identified, but these are separate events.
El nino is an hot water ocean current. When it changes its normal course the global climate is affected. It creates increased rainfall.
Kuriosho current el nino current
El Nino and La Nina are climatic events that result from the Pacific Ocean decadal current. They are not problems, but just plain old weather.
Also called El Nino, the CA current is Warm.
During an El Nino event, there tends to be fewer hurricanes in the Atlantic Ocean. This is because El Nino conditions typically create stronger wind shear over the Atlantic, which can inhibit hurricane formation and intensification.
Short answer: El Nino is a prevailing west wind blowing across the Pacific, usually in the late fall or early winter. For the long answer, see the related link.
El Nino is bad
It is believed that El Niño produces wind shear, which is a change in the speed and/or direction of the wind with altitude.