http://en.wikipedia.org/wiki/HDMI - HDMI is a newer digital audio/video interface developed and promoted by the consumer electronics industry. DVI and HDMI have the same electrical specifications for their TMDS and VESA/DDC links. However, HDMI and DVI differ in several key ways.

• HDMI lacks VGA compatibility. The necessary analog signals are absent from the HDMI connector.
• DVI is limited to the RGB color space. HDMI supports RGB, but also supports http://en.wikipedia.org/wiki/YCbCr - YCbCr 4:4:4 and http://en.wikipedia.org/wiki/YCbCr - YCbCr 4:2:2. These spaces are widely used outside of computer graphics.
• HDMI supports the transport of packets, needed for digital audio, in addition to digital video. An HDMI source differentiates between a legacy DVI display and an HDMI-capable display by reading the display's http://en.wikipedia.org/wiki/EDID - EDID block.

To promote interoperability between DVI and HDMI devices, HDMI source components and displays support DVI signalling. An HDMI display can be driven by a single-link DVI-D source, since HDMI and DVI-D define an overlapping minimum set of supported resolutions and frame buffer formats. In the reverse scenario, a DVI monitor that lacks optional support for http://en.wikipedia.org/wiki/HDCP - HDCP might be unable to display protected content, even though it is otherwise compatible with the HDMI source.

Features specific to HDMI, such as remote-control, audio transport, xvYCC, and deep-color, are not usable in devices that only support DVI signalling. However, many devices can output HDMI over a DVI output (examples: http://en.wikipedia.org/wiki/Radeon_R600 - ATI 3000-series and http://en.wikipedia.org/wiki/GeForce_200_Series - NVIDIA GTX 200-series video cards), ^{http://en.wikipedia.org/wiki/Digital_Visual_Interface#cite_note-HDMI2006SpecsAppC-7 - [7]} and some multimedia displays accept HDMI (including audio) over a DVI input. Exact capabilities vary from product to product.