I usually call those "hand distance", "elbow distance", and "kissing distance".
During a seminar a couple of years ago, Kajukenbo SGM Angel García showed us three distances for the purpose of self-defense:
- correct distance: you're out of reach of the punch/stab so the attacker has to step in (guy can still kick but you're pretty ok)
- error distance: you're in range for a punch/stab
- stupidity distance: trapping/grabbing distance
His point being that you should be out of range when the guy decides to attack you, keeping you safeish while giving you more time to react and forcing the guy to step in to make contact (which makes him more vulnerable). When he attacks, you enter and chain blows/throws, keeping the pressure up until he's not a threat anymore.
He trained us to do the techniques also from "error distance" and "stupidity distance" but he said that if we're that close when feces hit the proverbial fan, we've made a mistake before.