Brothers and Sisters and Friends (Oh my)

A friend loveth at all times, and a brother is born for adversity.
Friends love through all kinds of weather,
and families stick together in all kinds of trouble.
A friend is always loyal,
and a brother is born to help in time of need.

Proverbs 17:17 KJV, MSG, NLT

I talked to a couple friends and my brother yesterday. I love both my friends and my brother and my friends are like brothers. But what's the difference or is there one? The word here makes the observation that while a good friend loves you through thick and thin, your brother or sister is there at your worst times. It doesn't mean that your friend is not there when you are in trouble, but that your sibling is there. Another way of saying it is that God gives you friends or sends you as a friend to give unconditional love and support to another person, but God gives siblings to be there no matter what.