Friendship is not something simple, it is when two or three people become best friends no one can separate them as they come together to be together forever. Friendship can arise between men and women, boyfriends, spouses, relatives with any kind of bond, people of different ages, religions, ideologies, cultures, social extraction, etc. Even a friendship can be established between a human being and an animal (not for nothing the dog is the best friend of man).

Friendship relationships can be born in the most diverse contexts and situations: the place where we live, the place where we work, the school, the university, parties, meetings, the coffee we frequent, through other friends, social networks, etc.

Fiendship, however, have different degrees of rapport. From the friends with whom we feel more distant relationships, to those with whom the deal is so close that we consider them "best friends", giving that friendship a degree of superiority over other friendships.

Friendship not only arises with those who have more affinities in terms of tastes and interests, or with whom we have more similarity, but it can appear between very different people.