There's nothing like a grammatical rule to bolster the self-esteen and to present an opportunity for sneering at others.
Or so some people think.
The story of the words persons and people is long, and has been made complicated by the rule-makers.
In the 1800s some of them decided that persons should be used for a distinct number of individuals, and people for a great mass of folk.
Well, all I can say is, tell that to Chaucer, who was writing about a thousand people five hundred years before.
Anyway, what's the best thing to do?
Well, if you want to sound like everyone else then you'll only use persons when you're using formal legal language (which includes describing how many humans are allowed in a taxi or a lift. Oh, and the police use persons a lot, too). Unless, of course, you're on the Indian sub-continent, where persons is used much more often and freely.
While I'm here, I must just point out that even though the word people sometimes means a great mass of folk (as the pedants like to tell us), nowadays it's always safest to use a plural with the word. So people say people say, and not people says.
The main thing, though, is not to worry.
Words To Use Today: persons or people. Person comes from the Latin persona, which means either an actor in a play or his mask. People comes from the Latin word populum, which means a group of people sharing the same culture.