Red Dots Holographic

Both put an aiming point on the target with no eye relief and both leave you shooting with both eyes open, which is what makes them fast. Reflex red dots use an LED and a coated lens, run for years on a battery, and are smaller and cheaper. Holographic sights use a laser and a recorded hologram, cost more, and eat batteries faster.

The practical difference is the reticle and how it behaves. A holographic reticle stays the same apparent size behind a magnifier while an LED dot magnifies with the image, and holographic sights work better through a partially obstructed window. For most shooters a good reflex dot is the right answer; the holographic advantages are real but narrow.