Ondemand Water Heater

water heater
a heater and storage tank to supply heated water
An appliance for supplying hot water for purposes other than space heating or pool heating.
Water heating is a thermodynamic process using an energy source to heat water above its initial temperature. Typical domestic uses of hot water are for cooking, cleaning, bathing, and space heating. In industry, both hot water and water heated to steam have many uses.

ondemand
A type of streaming in which a clip plays from start to finish when a user clicks a link. Most clips are streamed this way. Contrast to broadcast.
mechanisms collect routing information to a destination address when a node has to forward a package to this address, but they do not store this information for later use as table driven mechanisms do. Examples for such mechanisms are DSV [DSV] and ABR (Associative-Based Routing) [ABR].
refers to the fact that City & Guilds English exams can be taken at any time and the examinations do not have predetermined examination dates like in the case of other examination boards.