The process of de-energization entails isolating machinery, equipment, or systems from a source of energy. In lockout tagout, however, de-energization does not mean simply unplugging a machine; it means preventing the accidental or inadvertent re-energization of a machine.
When a machine is de-energized, it should also be properly locked out and tagged out. Lockout tagout entails the use of certain devices that will make the safe de-energization and re-energization of a machine possible.