The words person and people are not related etymologically. Person comes from Latin persona, meaning "actor's mask; character in a play; person," while people comes from Latin populus, meaning "the people."
The first person ("I" or "we") refers to the person speaking, the second person ("you") refers to the person being spoken to and the third person ("he", "she", "it", or "they") refers to another person or thing being spoken about or described:
In grammar, we use the term first person when referring to 'I' and 'we', second person when referring to 'you', and third person when referring to 'he', 'she', 'it', 'they', and all other noun groups. Person is also used like this when referring to the verb forms that go with these pronouns and noun groups. 10.
A human being is called a person, and while this applies to an actual individual, it also, in grammar, means the type of person — first person being "I/me," second person being "you," and third person being "he/him," "she/her," or "they/them."
From Middle Welsh person, ultimately from Latin persōna (“mask used by actor; role, part, character”), probably via Middle English persoun and Old French persone (“human being”).
Any of three groups of pronoun forms with corresponding verb inflections that distinguish the speaker (first person), the individual addressed (second person), and the individual or thing spoken of (third person).
There are 21 meanings listed in OED's entry for the noun person, one of which is labelled obsolete. See ‘Meaning & use’ for definitions, usage, and quotation evidence.
Person is the most general and common word for a human being, of either sex and of any age or social grade, without emphasizing the fact that there is but one, or, if there are more than one, viewing them severally: as, I met a person who said, etc. Individual views a person as standing alone, or persons as standing seperately before the mind ...