We need to be careful when we say someone is our friend rather than an acquaintance and the reason is because we want people to trust us long-term.
A friend to me is somebody that I've gone in the trenches with, that know my wife, that know my children, that know my grandchildren, people we've been on vacation with, people that we have multiple dinners, we go to movies, we get to know each other, people that borrow things from you and you borrow things from.