friendship is what kind of relationship ?

Relationship means that you have contact/interaction with someone, you share something with someone and you are close somehow. This means that you have a relationship with everyone you speak with more or less frequently. This also includes your co workers, teacher, neighbours etc. What kind of relationship you have depends on you and that person. Family is the only kind of relationship you can NOT choose. The others you can choose, although it's already proved that the closest friendships we have are with people who live close to us and have kind of the same life (style) and age as we have. So if it comes to that one can ask himself if there is anything to choose at all since we seem to pick out/feel more comfortable with people who look the same/are the same as we are.