Add-in and Switch on

Add-in noun - A printed circuit that can be inserted into expansion slots in a computer to increase the computer's capabilities.

Switch on and add-in are semantically related. In some cases you can use "Switch on" instead a verb phrase "Add-in".

Switch on verb - Cause to operate by flipping a switch.

Add-in and switch on are semantically related. Sometimes you can replace phrase "Add-in" with "Switch on", this terms are similar.