The meaning of love is, strong affection for one another arising out of kinship or personal ties : attraction based on sexual desire: affection and tenderness felt by lovers: affection based on admiration, benevolence, or common interests. To feel great affection for someone is to feel love for someone. The meaning of unconditional is, not subject to any conditions. Unconditional love is to have a strong affection, attraction, and admiration for someone without any conditions, or expectations from the individual.
Unconditional love can mean several things to different people. To me, unconditional love is when you are loved even though a person knows your greatest imperfections. Their love remains steadfast even when you disappoint them. There is really nothing you could do to the person that has unconditional love for you, that would change the love they feel for you. The best example I can give of this type of love would be that of a mother, father, and child(ren). .
For some, unconditional love is purely romantic, or physical. For others, unconditional love only truly exists between family members, or between people in a committed, monogamous relationship. Unconditional love is not just a love shared between people. Animals are a great example of unconditional love. They will be by their owners as long as they are allowed to be. They don't care if you are smart, attractive, wealthy, or famous! Dogs are known as man's best friend because of their constant, unwavering love for their owners, and if part of a family unit, their "pack".
Children are a wonderful example of unconditional love as well. They give their love freely and without prejudice. There is no love like a love from a child to a parent, and also from a parent to a child. A child's love for a parent can also be described as love at first sight. Interestingly, this is not a behavior that is "learned", but rather it is part of a baby's natural instinct; they are born with it.