FRIENDSHIP

In my opinion, friend means the shoulder you can cry on. You can tell them what's on your feeling, your amazing stories and unexpected experience.

If you make friends, you'll meet a lot of people personalities. They can be generous, or rude sometimes. It makes us not very "introvert" and we'll have kind of "connection". This "connection" could be very useful when we're working. 

It can be easier for you to work / do whatever you want if you have "connection" friends. So, friend is to help each other.