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).
If you play games, refresh rate is something you might want to consider. Most monitors come with a refresh rate of 60Hz, which means you can only see 60 frames per second when you play (even if your game is getting 100 FPS, you can only see 60 of them on a 60Hz monitor). A 120Hz monitor provides a smoother gaming experience and allows you to play games in 3D at 60Hz for each eye.