DVI is the interface at the back of the TFT screen, instead of the DSub on CRTs, it allows for better/easier graphics control and quality (note your graphics card needs to have a DVi output to make use of the DVI connection of the screen... D10, not sure
Trust me I know what I'm doing... ooops, grab the cat...
Yeah as far as I know there is no such thing as a Dsub(male) to DVI(female) adapter but there is a DVI(male) to Dsub(female) basically like marneus said you can have a analogue (dsub) monitor plugged into an adapter for DVI which is in turn plugged into the graphics card with a DVI output. However, a graphics card with an analogue output cannot be coupled with a monitor that only supports DVI.
The Dsub has 15 pins aligned similar to a serial ports pins while the DVI has one wide pin surrounded by 4 regular pins to the one side of the plug and 24 other pins aligned in a square lined up formation. each of the pins on the DVI is flat and turned diagonal also. Most newer graphics cards either come with one DVI and one Dsub or both DVI and always come with adapters to go from DVI to Dsub.