Scott is right but it is a bit more comlicated. person is always focused on the individual, even when in plural (persons). We normally use people for the plural. People can also refer to the people of a place or culture. i.e.: The different peoples of Asia have varying religious beliefs.

1 person (singular) 2 people (plural)

I agree with the other comments. However there's one odd exception, "persons of interest," which is something that you might hear if you watch the news in English. The phrase is often used by the police in discussions about criminal investigations.