HDMI stands for High Definition Multimedia Interface, and it’s used for connecting high-definition devices like HDTVs and HD cameras and camcorders. HDMI connectors come in four sizes. The largest is Type A, there’s a Type B capable of higher data transfer speeds which may become significant in the future, and a smaller Type C (sometimes called HDMI mini) which is commonly used on cameras and camcorders. There’s also an even smaller Type D.
Annoyingly, high definition devices with an HDMI output seldom come with HDMI cables - these are optional (or do we mean compulsory?) extras. You need to make sure you get a cable with the right-sized connectors on either end.