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).
I'm not sure of the engish term but I think it's retinal persistence. the problem is that the eye has not the same refresh rate on all it's surface. I got sensitive eyes and that's why I'm very picky about refresh rates. i need 80Hz to feel comfortable when looking at the screen. any lower i can see it flash.