An energy-saving computer or peripheral device. Green computers, printers and monitors go into a low-voltage "suspend mode" if not used after a certain period of time. Laser printers especially waste a lot of energy when not in use, because of their heat-induced fusing mechanism.

Many contemporary CPUs can run at variable clock rates and can idle at lower speeds to save current. When input is detected, they revert to full-power. The "green" concept also includes using less packaging materials, recycling toner cartridges, providing a return location for used batteries and sending e-mail rather than paper mail.