Conversation so far:
when did apple come out with retina display
Retina Display was introduced with the iPhone 4 in June 2010.
what is in apple's retina display
Retina Display refers to devices and monitors with a resolution and pixel density so high that a person is unable to discern the individual pixels at a normal viewing distance.

Question: how does the display work
Self-contained rewrite: how does apple's retina display work