Regza-Link is Toshiba's inter-connectivity protocol that enables you to control Regza components with one remote control. There are no Regza speakers, but you can control the volume of fixed output speakers attached to the RCA outputs on Regza televisions with a Toshiba TV remote. Regza is also the designation that Toshiba gives to its top-of-the-line LCD televisions.
Fixed Audio Outputs
For sending audio to external speakers, a receiver or amplifier must be employed, since the outputs on the Regza televisions are line level outputs. With fixed audio outputs, external speakers are connected to the receiver or amp. You can still regulate the volume of the external speakers with the TV remote.
The Toshiba TV remote has a switch with which you can select your television and other devices for control. The choices depend on which model of Regza television you own, but you'll sometimes see dedicated control buttons for DVD or Blu-ray players, too. Devices must be connected using HDMI, but with that, Regza-link lets the television control everything, without you having to reach for another remote control.
Optical Audio Output
Optical audio output is a digital stereo signal transmitted by light. For sending audio to external speakers, the receiver or amplifier must be equipped with an optical audio input. Many components have optical output with digital signals now being the norm. With optical audio output, external speakers connected to the receiver or amp's processing allow the volume of the external speakers to be regulated by the TV remote.