There are so many levels to love, that I can only express a few of them here. These are the ones we see most in life. Friendship starts this list off. Yes, it doesn't seem like it, but we do feel love towards our friends, this is what helps us get along so well, and why we miss them when we don't see our friends for a long time. It's also why we hold certain friends over others no matter what happens. Sometimes, the bond between friends deepens to the point where a stronger bond of love is made, making them family.
Another level of love, are for our siblings and other family members. Even though we do things to our family members, and sometimes we don't like some of our family, that bond is still there. It's this family bond level of love that brought about the phrase, blood is thicker than water. We will do things for our brothers, sisters, mothers, fathers, and children before we would even consider doing them for anyone else. Many wars have been started because of this family level, brother avenging brother or father, father protecting his wife and children, or even vice versa. This simple family bond can even extend to include our pets, amazingly enough, and that is a good thing.