Beginning in 2005, Apple released several computers with a Mini-DVI port, including the 12-inch PowerBook G4, Intel-based iMac, the MacBook Intel-based laptop, the Intel-based Xserve, the 2009 Mac mini, and some late model eMacs.
The port was only used until 2008 when it was replaced with the Mini DisplayPort. The port is used instead of a full-size DVI connector to save physical space while allowing the computer to be connected to a DVI-D display.
Sources: EveryMac, B&H Photo Video, Wikipedia
