Do we know what love is?

We all have different meaning of what love may be.. but do we actual know what it is?
If the feeling you have is love.. then what is love?
"If you know the reason for why you love that person it's a crush.. and if you don't it's love" said by a wise person. Doesn't that make the word "love" something that can not be explained? So the feeling you have.. do you know if it's love or some other feeling that just doesn't have a word?