DVI
From Mac Guides
DVI (Digital Video Interface) is a standard for connecting display devices, such as a monitor, to a computer.
DVI cables can send many signals, making them highly flexible. DVI-D only carries a digital display signal for use with flatscreen monitors and other, newer, digital display devices. DVI-A cables carry only a standard VGA signal for use with older monitors and projectors. DVI-I carries both types of signals. DVI also allows for signals suitable for use on a television to be sent.
Adapters
In order to make proper use of a particular signal type from a DVI cable, you will need an adapter. Many companies make such adapters, including Apple themselves.
Generally available are DVI-A or DVI-I to VGA adapters, and DVI to S-video adapters.
mini-DVI
mini-DVI is used to provide monitor connectivity on many laptops, such as Apple's PowerBooks. mini-DVI carries exactly the same data as a normal DVI connection, but fits this into a smaller space. In order to use this, you will need a suitable adapter, such as mini-DVI to VGA, mini-DVI to DVI, or mini-DVI to S-video.
