DVI, HDMI, Component, S-Video, Composite... Confused?
Hopefully we can help clear it up a little for you.
So What is DVI? DVI Stands for Digital Visual Interface. DVI is the
digital interface standard created by the DDWG (Digital Display
Working Group,
www.ddwg.org). Led by Compaq, Fujitsu, Silicon
Image, Hewlette Packard, NEC, Intel and IBM, the DDWG's main
objective is to "address the industry's requirements for a digital
connectivity specification for high-performance PCs and digital
displays." - per the DDWG statement, available at www.DDWG.org.

With the need to accommodate both digital and analog monitors,
this new digital interface standard was created to convert analog
signals into digital signals. DVI's High bandwidth capabilities make
it ideal for HDTV connections. Also available in dual link, DVI can
reach higher resolutions still.

Using the pictures on the right, you can determine the type of
connection you need, be it DVI-D, or DVI-I. To determine the actual
signal being used you will have to consult your manual for the device
being connected. For more information concerning DVI:

DVI-D Digital. Connectors on DVI-D do not have the 4 additional
pins, these are meant for carrying Digital signals only. Digital must
be connected to Digital and Analog to Analog. While you can plug a
DVI-D cable into a DVI-I socket, both devices you are connecting
must support Digital signal format. Analog to Digital will not work.

DVI-I Analog or Digital. Connectors are basically the same as DVI-D
with the exception of 4 added pins. You'll notice both have 3 rows of
pins to the left, and one horizontal pin to the right. The DVI-I
connection has 4 additional pins, 2 on top and 2 on bottom. These
pins are used to carry the needed signals for RGBHV analog video.
(Red, Green, Blue and Horizontal). You can use DVI-I on both DVI-D
and Analog connections, but remember, an analog device will not be
compatible with a Digital device.

Adapters HD15 to DVI-I (VGA to analog) adapters exist to connect
your analog device to a analog display through DVI connection.
Remember that while DVI-I is usable for Digital display, the extra 4
pins make it usable for Analog as well. The needed adapters is
available in our store.