A.H.
In my opinion there are many types of friends. I have my close friends, that I talk to almost every day and know everything about me. There are my friends that I see or talk to once in a while and know the basics. And there are the friends that I see once in a long while that are like a good piece of chocolate, very good for a short period of time. All are important and I know all would do anything for me as I would for them. It's just some are closer than others.
Each friendship is different, with some friends you have to talk everyday and see each other once a week to make it work, with others you can talk once a year and never see each other and still be best friends. It all depends on the people and where they are at in their lives.
There is no right answer for a friendship... it's what ever people want it to be.