Disable
Disabling a device effectively means putting a device on standby, meaning that it will be unresponsive to any commands unless it is enabled again.
Enable
Enabling a device makes it responsive again, by enabling a device you are allowing it to respond to your commands.
Turn Off
By selecting this option you are turning the device off as if you are flicking a switch for a light to switch it on or off. After selecting this option the device Icon should change to show an off state.
Turn On
By selecting this option you are turning the device on as if you are flicking a switch for a light to switch it on or off. After selecting this option the device Icon should change to show an on state.