Mini DisplayPort is the current digital standard on all current Macs to transfer video to an external display or TV. It has been introduced in 10/2008 with the release of the Unibody MacBook and MacBook Pros and has gradually been adopted on all other Macs.
MDP is capable of transmitting video, and since 2010, audio too. MDP is a miniaturised version of DisplayPort. It is also license free and can support resolutions of up to 2560 x 1600, which Mini DVI and Micro DVI are not able to do.