As I understand it, unconditional love is simply love that is freely given and not based on any requirements being met. It is not loving someone and glossing over their faults, it is loving someone while being aware of their shortcomings and loving them anyway. It is not required that the people I love do anything for me, love me in the same way, or love me at all. All categories of love can take an unconditional form- familial, friendship, romantic, what have you. And I don't think unconditional love equates to everlasting love. Just as other forms of love can fade with various causes of relationship deterioration, so can unconditional love. It can transform into conditional love and then maybe not love at all. And unconditional love can grow from conditional love as well.
My mom's more of a conditional love sort of person. I mean, she claims unconditional love toward her children but with anyone else- even her sisters and my stepdad- her love is based more on if they fulfil her requirements. She has more love to give to people who give something to her in return, whether it be kindness or helpfulness or something like that. She doesn't really have the time or patience to love people who don't give back. Also she has a hard time accepting people's inherent faults so there's that.
I think I'm an unconditional love person. I love people a lot. For no reason other than that they make me happy and it makes me happy to love them. I've loved people unconditionally and now no longer do, and that's fine. That's just how those relationships went. I love people unconditionally now that I probably won't in the future due to the changing nature of our lives etc. It's like... if I say "I love you" and you ask "why?" all I can say is "because." There is nothing specific you do to make me love you, and there's no real reason for me to love you. I just do. I think that's pretty much all there is to it.
But being aware of my general inclination toward unconditional love, I do kind of have to be wary not to gloss over people's faults or hurtful behaviour. I have to be able to recognize when a person is hurting me or others, if it's intentional or not, and call them out on that. I love people, but I would hate to be taken advantage of due to that.