Love is when you see a very flawed individual and someone with a bad past and behaviors. And you are hopeful for them because of their potential and changed outlook.
Love is seeing them with a significant other and knowing that you have zero chance of ever being with them, because of circumstances or past events, and yet would do anything and everything for that person. And you have done that, giving up all money/time, and taking in personal pains, just so you can see a smile, or knowing they are in a better place.
Love is for an individual totally unrelated to you, isn’t an obligation (family members) or part of lust.
Love is knowing that they will be alright at the end of the day. And you shared something special with them. And if you don’t see them for the next 50 years, you would hope for their happiness every day.