Unconditional love is a term that means to love someone regardless of one's actions or beliefs. It is a concept comparable to true love, a term which is more frequently used to describe love between lovers. By contrast, unconditional love is frequently used to describe love between family members, comrades in arms and between others in highly committed relationships. It has also been used in a Christian context to describe the belief in God's love for humankind through the forgiveness of Christ.
Unconditional love separates the individual from her or his behaviors. However, the individual may exhibit behaviors that are unacceptable in a particular situation. To begin with a simple example: one acquires a puppy. The puppy is cute, playful, and the owner's heart swells with love for this new family member. Then the puppy urinates on the floor. The owner does not stop loving the puppy, but needs to modify the behavior through training and education. Unconditional love is sometimes most overlooked.
Unconditional Love: is the reverse it would be the Love expressed by the Puppy, while Humans wish to Change, Modify or Alter the behavior of the Puppy, the Puppy continually returns with genuine and loyal Love.
Another example is a child. The parent loves the child unconditionally at the moment of its birth. As the child grows, it exhibits a selection of behaviors. One day the child writes on the bedroom wall with a crayon. The parent does not suddenly stop loving the child. Rather, the parent teaches (educates) the child where it is appropriate to write with a crayon and where it is not.
Professor Mario Beauregard, from Montreal University's centre for research into neurophysiology and cognition, used MRI to study active areas of the brain of people, who were most likely to experience unconditional love. Subjects were asked to call to mind feelings of unconditional love. Researches saw 7 active areas in the brain. Three of those areas were similar to regions in the brain that became active when it came to romantic love. The other four were different, which means that the feeling of love for someone without the need of being rewarded is different from the feeling of romantic love.
In his study professor Beauregard found that some brain areas that turned on when a person felt unconditional love also engaged in discharging dopamine, chemical that plays a role in sensing pleasure. 
While the phrase has never been used in its official teachings documents the then head of the Roman Catholic Church, Pope John Paul II was recorded as saying during a homily in San Francisco, in September 1987, that God "loves us all with an unconditional, everlasting love". He explored issues touching upon this theme in his work Dives in Misericordia (1980) in which the parable of the Prodigal Son becomes a framework for exploring the issue of God's mercy. The civil rights leader Martin Luther King Jr. was quoted as saying “I believe that unarmed truth and unconditional love will have the final word in reality”.
Neopaganism in general, and Wicca in particular, commonly use a traditional inspirational text, Charge of the Goddess , affirming that the Goddess's "law is love unto all beings". In Buddhism Metta Sutta advices humans to love the all living beings including animals, just as a mom with only one son love him unconditionally.
Aleister Crowley, despite the confusion surrounding his teachings and philosophy, was also a preacher of unconditional love: "the law" is essentially an invitation to another to "do as thou wilt" - meaning, to have no controlling expectations or stipulations, requirements or conditions, but to Love and accept others unconditionally, allowing them to live their personal Truths.
Unconditional Love is used to denote Agape love. Agage love is the God kind of love. It is not Felio love which is brotherly love. It is not Eros love which is erotic. It surpasses the human understanding in that "God so loved the world that he gave his only begotten son that whosoever believeth in him shall have eternal life." (John 3:16) The exact meaning and it's definition in its entirety can be found in Strong's Exhaustive Concordance.