What is the difference between Prime and Standby Power Generators

Prime power refers to the use of a generator for continuous operation where there may be no mains power supply available or the mains power supply acts as a source of back-up power to the generator should it run out of fuel. Standby power generators are used for back-up power when the mains power supply fails and in a server room or data centre or other critical application, will provide a temporary source of power for an uninterruptible power supply.