It seem that a comparison between family and friend is probably inappropriate. Each of these plays a different role in our life.
Family is a inseparable part of our life. Family is the inception of our existence. Our home is where we were born , and our parents , granting the first breath to us , were also the first teachers who teach us about simplest things such as wearing clothes and so on . Thanks to our parents, a vast mount of experiences, making us understand life better and become more confident in the future, have been transmitted to us. To some extent, family ties are unbreakable and exist forever. For example, even we were adapted children, we couldn't stop seeking our real parents who have never looked after us at all.
Friend , on the other hand, share school life, emotion and secrets with us. As tutor, our friends assist us in learning difficult subjects and teach us how to learn in a more effective way. Moreover, sharing our emotion and secret, which can make us inhibited when telling our parents about it, with them tends to a effective way to reduce the pressure on us.