The MacBook is also the first notebook to be released with DisplayPort. DisplayPort is a royalty-free, license-free design that was created by VESA as an alternative to DVI and HDMI.
HDMI is a superset of DVI, which is to say that everything that DVI can do, HDMI can do also. This makes it very easy to connect DVI devices to HDMI displays via a passive adaptor. DisplayPort is a completely different signaling protocol that has both technical and marketing advantages. The marketing advantage is that DisplayPort is royalty-free, which means that it’s cheaper for PC manufacturers and monitor manufacturers to implement a DisplayPort-only chain than an HDMI-only chain. The technical advantages are lower power, reduced lines (smaller cables both internally and externally), as well as a micropacket architecture where the clock is integrated into the signal. For laptops, DisplayPort theoretically allows the same signaling to be used for the internal display as the external display. The current MacBook, however, continues to use traditional LVDS module.
From a practical standpoint the use of HDMI adds additional costs, particularly on the monitor end, while the use of a DisplayPort front loads the processing on the output device (the computer), making monitors cheaper, while also remaining royalty free for the PC/notebook manufacturers. The DisplayPort-only 24” LED Cinema Display is a good example of what can be done with a DisplayPort-only design; although the $900 price tag may seem higher than the competition, the monitor features a top-of-the-line LG Philips H-IPS panel with LED backlight technology, which cannot be found elsewhere. Monitors such as the HP DreamColor line use DisplayPort to enable 10-bit color support without paying the added royalties required for implementing a HDMI port with Deep Color capabilities. The pervasiveness of HDMI for consumer electronics means that notebook and PC manufacturers will always need to include support for DVI or HDMI signaling methods and so the use of DisplayPort-only is going to be restricted to PC monitors.
Apple has chosen to go with their proprietary, but open and freely-licensable Mini DisplayPort connector. While the Mini DisplayPort offers the same 20 pins as the larger DisplayPort, the mini version relies on a friction fit to reduce the connector size. This allows smaller notebooks to be manufactured. Unlike the Apple Display Connector (ADC) which rolled DVI, USB, and power into a single cable but never found use outside the Mac, DisplayPort is still a young enough technology where the standards are still evolving. The forthcoming DisplayPort 1.2 standard is set to officially include Apple’s Mini DisplayPort.