Wiki explains it as: Love is the emotion of strong affection and personal attachment.
I highly agree with this. But it doesn't have to be an attachment to a person or people, I'm not saying its not because there are lots of people in my life i deeply love.
Although it can also be a love of:
A TV show: Mine are MASH and Friends.
A sport: Hockey and rugby.
A item of clothing: My green lace dress and Vintage crocodile skin bag.
I do also love my Mum, dad, brother, dog, boyfriend, great aunt and all the rest of my family very very much.
What defines your love?