Mini DisplayPort is a compact version of the DisplayPort connector introduced by Apple in 2008. Mini DisplayPort is free to license, and in 2009 it was included in the official DisplayPort 1.2 spec. In 2011 Apple and Intel announced the Thunderbolt format, which used the same physical connector, but significantly different protocols.
Screen refresh rate is the number of times an image on any type of monitor or television is reconstructed per second. This is measured in hertz.. (Hz).
With 120Hz, 240Hz, and even 600Hz, refresh rate gets a lot of attention in the marketing of new HDTVs. What it is and how it works is interesting, but why it exists is even more so. And it can have a profound effect on the picture quality of your HDTV.