Now, I think they are both part of the equation, maybe one leading to the other or something. Well, enought rambling on my part. I did find something that I think captures some of the different nuances between love and infatuation. But, I still think the best definition of love is described in the bible. It is one set of glands calling to another.
Love is friendship that has caught fire.
It takes root and grows, one day at a time. Infatuation is marked by a felling of insecurity. You are excited and eager, but not genuinely happy. There are nagging doubts, unanswered questions, little bits and places about your beloved that you would just as soon not examine too closely. It might spoil the dream.