Whats love?

Perhaps the question that will not give a correct answer 100% no more than a thousand years, just because people feel love differently, as long as we humans are different. There are some who believe that love is pure attraction. Maybe it's a chemical formula or just a mating ritual, but at the same time can be a miracle of God on us as to forget that life is so hard, who knows? I think there are hundreds of explanations, formulas, imagination; love is everything or nothing; who knows?