What is the plug called with the prongs that goes into the top of transmission on 95 g20 van?

The plug with prongs that connects to the top of the transmission on a 1995 GMC G20 van is typically referred to as the transmission range sensor connector or the neutral safety switch connector. This component is responsible for transmitting information about the transmission's position to the vehicle's electrical system. If you're looking for a replacement, it's best to consult a service manual or an auto parts store for the specific part number.