When using an HDMI to DVI adapter, the adapter will work with two DVI ports which are DVI-D and DVI-I ports
DVI is a digital signal that has the same format as the video portion of HDMI. However, DVI doesn't carry the audio signal whereas the HDMI does.
This means that if you are only using the video signal you can use a simple DVI to HDMI plug-adapter that changes the physical connections.