A person who studies the origin of the words and its meaning is called an etymologist. Etymology is a branch of linguistics. I think all these are terms are named in English language, in every developed language there is a different term for each studies.
The wisdom of using an electric heater depends on the per kilowatt cost in your region. 1  If your heater has a 1000 watt rating and your cost of electricity is $0.15/Kwh your cost to operate for one hour would be $0.15. 2  If the element is activated 10 hours out of every 24 hours your cost per day would be $1.50.
Upfront Costs. Though they are less expensive to operate, electric heat pump pool heaters cost more upfront than both gas and electric resistance heaters. Heat pumps can cost up to $5,000, while the majority of gas and electric resistance heaters are available for around $1,000 and $2,000 respectively. The cost for installing heat pumps and gas heaters averages about $300 to $500, including labor and materials. The cost for installing an electric resistance heater can be two to three times this price because of necessary wiring upgrades to handle the required amount of electrical current.