(the third-person plural) A group of people, animals, plants or objects previously mentioned.
(the third-person singular, sometimes proscribed) A single person, previously mentioned, especially if of unknown or non-binary gender, but typically not if previously named and identified as male or female.
(indefinite pronoun, vague meaning) People; some people; people in general; someone, excluding the speaker.
There (especially as an expletive subject of be).