IEEE Standard Dictionary of Electrical and Electronic Terms: Sixth edition Std 100-1996

Uninterruptible power supply module (electric power systems in commercial buildings):

A) A device or system that provides quality and continuity of an ac power source.

B) A system designed to provide power automatically, without delay or transients, during any period when the normal power supply is incapable of performing acceptability.

Offline operation (emergency and standby power):

A) Pertaining to computer systems not under direct control of the central processing unit

B) Pertaining to uninterruptible power supply systems whereby and inverter is off during normal operating conditions.

Online operation (emergency and standby power):

A) Pertaining to equipment or devices under direct control of the central processing unit.

B) Pertaining to uninterruptible power supply systems whereby an inverter is on during normal operation conditions.