WHAT IS A RED DOT SIGHT AND HOW DOES IT WORK?
RED DOT SIGHTING TECHNOLOGY
The red dot sight technology invented by Aimpoint allows a shooter to do what comes naturally — keep both eyes open while focusing on a target. When a shooter is target focused and brings their sight into view the brain notices the red dot through the lens of the sight.
When the red dot is on the target, you’re on target. As long as you are properly zeroed, there is no need to center the dot in the sight. This allows for quick target acquisition. It is this combination of speed and accuracy that makes red dot sights the preferred choice for beginners and experts alike.
Red dot sights are made without magnification or optical distortion. Unlike lasers, which project a red dot onto a target, red dot sights are all internal allowing only the shooter to see the red dot on their target.
The red dot sight uses a LED (light emitting diode) which is completely eye-safe compared to a laser which produces an emission that can be harmful to your eyes.
The dot in red dot optics have different sizes and is measured in MOA, which stands for "minutes of angle".
RED DOT SIGHTS VS RED DOT SCOPES AND OTHER RED DOT OPTICS

There are various kinds of optics on the market. For accuracy and quick target acquisition, red dot sights are superior to iron sights and magnified scopes in several ways.
There are different terminologies when it comes to red dot sights. A "sight" is an optic without magnification while a "scope" is an optic with magnification. But the word scope is commonly used in the US instead of the word sight. So, it is not unusual to see the terminology red dot scopes.
RED DOT SIGHTS:
The single red dot has been proven to be the fastest type of aiming reticle and provides the greatest hit probability on moving targets. Red dot sights allow you to remain focused on the target.
Shooting with both eyes open means that you remain in touch with what is going on around you.