Dot Name - This is the product name to look for.
Company - This is the company who makes the product.
Emitter - Closer/Open emitter. Open emitters do not protect the projection of light from the emitter to the glass of the dot. Closed emitters close off the projection space with metal and glass, effectively creating a little box in which the red dot operates. Open emitters may have issues projecting their dot onto the glass if debris, water, dust, etc. gets in the way of the emitter. Closed emitters may have issues with internal fogging with rapid temperature changes, but most closed emitters have an anti-fog treatment to mitigate this. Closed emitters are generally more robust than open emitters.
Footprint - This is the patternon the bottom of the optic that it uses to attach to the gun, or mounting plates. If you want more information on these footprints and what they're compatible with, take a look at optics-info's red dot footprint list.
Incl. Adapter - This lists what footprint adapters are included. Adapters are used to mount dots on common rail systems like Picatinny, at various heights. These are often referred to in terms of "cowitness", or, where the irons align with the dot. "Absolute" means the dot will be perfectly overlaid with your irons. "Lower 1/3" means your irons will take up the bottom third of the optic. "Low Profile" is something arbitrary per brand.
Color - This is the color of the dot projected onto the glass. There is much debate over red vs green. Green has reduced battery life, but may perform better with some astigmatisms. Red provides better battery life and better contrast against most objects. Gold is... Something else that has yet to be proven as well as red or green.
Reticles - This is what the dot looks like when projected onto the glass. MOA refers to the size of the dot. Slashes denote a dot with multiple reticle settings.
Adv. Battery Life - Battery life as advertized by the manufacturer.
Solar - Does this optic contain a solar cell? Solar cells allow small amounts of light to recharge the battery, lengthening the battery life of the optic.
Shake-Awake - Does this optic have shake-awake? "Shake Awake" optics will automatically turn off after a period of stillness, and when shaken, the reticle will turn back on. This helps conserve battery life.
Brightness - The number of brightness settinigs available for this optic. "DL" means daylight settings, "NV" means settings only visible under night vision.
Battery - The type of battery the optic takes.
Batt. Tray - The position of the battery tray on the optic. Side-tray batteries can be changed without removing the optic from the gun and losing zero. Bottom-tray batteries require removal of the optic.
Housing - The material the body of the optic is constructed from.
Int. Irons - Whether or not this optic has integral rear iron sights.
MSRP - Manufacturer Suggested Retail Price. This is how much the company who sells it says it should be sold for. You may find scalpers selling it for more. You may find sales selling it for less. Discontinued optics may not have an MSRP available.
Notes - Any further information on the optic.