To see people you know in your dream, signifies qualities and feelings of those people that you desire for yourself.
To see people you don’t know in your dream, denotes hidden aspects of yourself that you need to confront.
To see people from your past in your dream, refers to your shadow and other unacknowledged aspects of yourself.
It can represent a waking situation that is bringing out similar feelings as your past relationships.
Also see “Crowd.”