What is love really? Is there any such thing?

I hear and say I love you all of the time, what is it? Is it just a conceptual emotion? Sometimes I don't feel the love and other times I do I know that there are things like dopamine, peptides and serotonin involved. And want to know from a scientific point of view what love is. I've heard that hormones can be triggered from falling in love, which ones? And for how long? Is it really the love for my friends or the love of emotions I get when I'm around them. It would be funny if the love of emotions was the root of all evil!!!