Aristotle characterized friendship into three types, an interesting framework to consider: friendship of utility, friendship of pleasure, and friendship of the good.
Friendship of utility might be our relationship with our favorite hairdresser. It is a relationship established on mutual practical benefit and may terminate as soon as that benefit is over for whatever reason, but we behave in a friendly manner while it lasts.
Friendship of pleasure would pertain to those we spend time on a shared activity like golf, bridge, movie going or wine club If we lose interest in that particular hobby or location, the friendship of pleasure may also end once the ease to get together is gone.
Friends of the good is when two people enjoy each other for their own sake because they find in each other an affinity of character that does not require externalities like a business exchange or hobby. In those cases, as Aristotle puts it, our friends become mirrors to our souls, helping us grow and become better persons just because they care about us. This kind of distinction could also apply to our relationships with family members or with our companion.
Aristotle was not a Stoic. The Stoics would have said that the only friendship that truly deserves to be called a friendship is that of the good.
from Massimo Pigliucci’s “How to Be a Stoic” pg 198