Friendships are the family we make - not the one we inherit. I've always been someone to whom friendship, elective affinities, is as important as family.

This quote means that the friends we have are just as important as the family we were born with. Friendships are a type of family we make by choice, rather than one that we are born into, with no control over who is in it. People who feel this way may place great importance on their friendships and the relationships they form with people, rather than the family they inherited.