Voting down seems petty so I didn't (not even sure if I can), but this is a simple dictionary question. A portrait is a representation of a person or group of people.
EDIT: clarification to remove unintended snark: A representation of an individual or of a group (say a sports team) are recognisably portraits whereas a street photograph which happens to include people is not. If there is a distinction it is in intent, if the principal subject is one or more people it is probably a portrait, otherwise not. Whether photography, pencil sketches or paintings.