Utility, is a source derived from commercial power or an auxiliary generator which is used as an alternate source for the critical load.

An electric generator is a device that converts mechanical energy to electrical energy

Automatic Transfer Switches are for transferring electrical distribution systems or individual electrical loads from one power source to another typically due to an out of limit voltage or frequency condition on the primary source

Input Switchgear (Switchboard) is used for electrical distribution inside a building, which includes input and bypass feeder breakers to a UPS

Surge Protection devices are designed to reduce high energy occurrences caused by a variety of sources.

"Uninterruptible Power System" - A system which provides conditioned and uninterruptible power to a critical load.

The battery provides an alternative power source in case the main power source becomes unavailable for whatever reason. Can be different technologies depending on the use and environment.

Flywheels work by accelerating a rotor (flywheel) to a very high speed and maintaining the energy in the system as rotational energy. When energy is extracted from the system, the flywheel's rotational speed is reduced as a consequence of the principle of conservation of energy; adding energy to the system correspondingly results in an increase in the speed of the flywheel.

Output Switchgear (Switchboard) is used for distribution downstream of the UPS and usually includes a UPS Maintenance Bypass Breaker arrangement.

The static switch connects the bypass source to the critical bus in the event of a UPS failure.

A power distribution unit (PDU) is a device fitted with multiple circuit breakers designed to distribute electric power, especially to computers and networking equipment located within a data center.

Critical Loads are usually defined as electronics systems (IT, Process Control or Medical Imaging) required to keep operational during power anomalies including failures