For as long as I can remember, even before the military, no one really had any idea that the term of EVERYDAY CARRY actually applied to what they had in their pockets, purses, briefcase, backpack, car, etc. Since then, EDC has become more prevalent and understood as a basic needs kit or survival gear, depending on what you happen to be doing.
The basic desk jockey that does the 9-5 job, probably has this type of day: wake up, morning routine, travel to work, work-lunch-work (maybe dinner & work), travel home, evening routine….repeat. They usually only carry the basics, such as wallet, cell phone, countries currency, and car/house/work keys.
The extreme Armageddon type are usually prepared for everything and then some. examples would things like: keys, wallet, currency, cell phone, led “blind you/ hurt you” flash light, 2 or 3 different situational dependent knifes, survival kit, freeze dried food packs, case of water, camel back or other type of 3 day pack, assault vest with body armor and plates to stop large caliber bullets, two pistols (concealed carry/ operational carry), two rifles (short and long range), sufficient amount of magazines loaded with ammunition to stop even the most drugged-up individual (shooter preference), blowout kit (s), weapon for passenger in the event that one shooter is not enough to control or finish the problem, etc.
Shooters will argue till the end of time which ammo is the best ammo to use in a hand gun and rifle. I am not going to get all scientific on you, but will give you my biased opinion on what I think is “efficient” in stopping/eliminating the threat.