They're both digital connections and can be used with upsampling DVD players to avoid extra D-A and A-D conversions, especially useful with digital projectors.
HDMI also carries audio signals (main difference). It is becoming more popular and probably will replace DVI in the future.
If you have a DVI projector and a HDMI DVD player (as I do) a HDMI-DVI adapter can be used for the video.
HDMI also carries audio signals (main difference). It is becoming more popular and probably will replace DVI in the future.
If you have a DVI projector and a HDMI DVD player (as I do) a HDMI-DVI adapter can be used for the video.