Quote Originally Posted by The Tig Kid View Post
Who can tell what these are all about? Or point in the direction to find out.

Thank you,
You can Google for all the details, but the thumbnail sketch version is that the IGBT is more durable and can handle more power than a MOSFET, while the MOSFET can switch at higher frequencies. IGBT is the newer technology and better suited to high current uses like welders and plasma cutters.