Electric hot water systems are the most common type of hot water systems in existing houses, however due to their large electricity consumption the Australian government has banned their installation in new builds or houses with natural gas connected to the property.
Electric hot water systems work similarly to a kettle, wherein an electric element simply heats the water for home use. They are available in a storage unit where the hot water is kept in a large tank at between 60-80°C ready for distribution, or instantaneous model where the water is heated by the electric element as it flows through the system giving a continuous stream of hot water. The instantaneous models however are a lot less common due to their excessive electricity consumption above that of even an electric storage unit.
For a detailed explanation on how all types of electric hot water systems work see here: https://www.yourhome.gov.au/energy/hot-water-service