The dictionary defines 'friend' as
- a person attached to another by feelings of affection or personal regard.
- a person who gives assistance; patron; supporter.
- a person who is on good terms with another; a person who is not hostile.
- a member of the same nation, party, etc.
I'm sure we can do better than that though - A true friend is someone with whom you can be fully self expressed. How does that sound? The liberty to be completely and unabashedly yourself with someone else (or elses) is a real pleasure. Unconditional love mixed with a commitment to you being the best you you can be. I would exclude 'friendships' built around being feverish, selfish little clods of ailments and grievances, complaining that the world will not devote itself to making you happy as Shaw would call it. That's just one sod propping up another. The sublime pleasure of slipping into comfortable youness with someone you trust completely can never be undervalued. The opportunity for robust debate where you can engage in vigorous discussions without trampling on the opinions of others or having your own trampled upon is a must too!
Friends come and go. It's a simple fact. Sometimes that parting is painful, sometimes a relief. As the seasons of life come and go aligned entities enter and exit our lives. The can touch us deeply or touch us briefly and then move on as their own journey winds blow them somewhere else. Some are more teachers, some are more students. In the words of Anain Nin “Each friend represents a world in us, a world possibly not born until they arrive, and it is only by this meeting that a new world is born.”.
Can you get this online...? I doubt it. This can only be gotten in face to face interactions, time spent together and laughs shared. Anything else if just a synthetic parody.