There are two types of geyser available in the market.
Instant geyser
Storage geyser.
The Instant Geyser, can supply warm water at such optimum temperature immediately, consumes 3 KW to 4.5 KW of energy. It is also called tank-less geyser because of no tank storage comes with it to store the water.
Hot water delivered to you instantly whenever you switch it on.
Whereas, the Storage Geyser consumes only 2 KW of energy. Though, it will take more time as compared to the instant geyser for heating the water.
Moreover, storage geysers have tank storage that can store a sufficient amount of warm water.