DVI to DVI Cables are commonly used to connect a computer monitor to the system graphics card, providing the signal you see on your computer screen. There are different types of DVI to DVI cable; Single Link, Dual Link, DVI-I and DVI-D. Depending on your graphics card and your monitor resolution and indeed the type of ports available will determine which type of cable you will require.
It is important to remember that there are two forms of single link DVI cables. DVI-I cables can carry either digital or analogue signal, but DVI-D cables only handle digital signals. DVI-I cables have an extra four pins and will not fit into a DVI-D port.