Okay now I have three questions
1.How do reflex sights work
2.Why are they called "reflex" sights
3.Are they different from red dot sights, and if so, how?
I have to answer these out of order, so check it:
3. A "red dot" sight is a type of reflex sight.
1. Simple holographics. They use clever lights and reflections to project a "floating" point of light inside of the plastic housing of the sight.
2. Because of they way they are built and mounted, reflex sights cannot be used for precision shooting, they were designed solely with the purpose of quickly drawing your gun and shooting at a target - they're meant to be used on reflex, they work as an assist to a shooter that normally has to reflexively blindfire in battle (because you absolutely CAN NOT use iron sights for quickly drawing your gun and shooting). Good marksmen with carbines and handguns actually learn how to aim WITHOUT using their iron sights because you simply can't take the time to line up the frontpost while you're getting shot at. A reflex sight simply makes this an easier maneuver.