Love is defined in one word, though it involves many issues such as trust, honesty, and such. In my opinion Love is tolerance.
If you can tolerate someone, that means that you care for them so much that you can accept them or tolerate them and all their habits, and mistakes.
Infatuation, I would say is more like lust, but all that means is that the sex is good, and perhaps you have a lot of fun together. It does not mean that you have enough heart and feelings for them that you can put up with everything thing else.