from the online Wikipedia:
Agapē (written αγάπη in the Greek alphabet, and pronounced /aga̍pe/ or /a̍gape/), is one of several Greek words meaning love. The word has been used in different ways by a variety of contemporary and ancient sources, including Biblical authors. Many have thought that this word represents divine, unconditional, self-sacrificing, active, volitional, thoughtful love. Greek philosophers at the time of Plato and other ancient authors use the term to denote love of a spouse or family or affection for a particular activity, in contrast to philia, an affection that could either denote brotherhood or generally a non-sexual affection, or eros, an affection of a sexual nature, usually between two unequal partners, the lover (eraste) and beloved (eromenos). The term is rarely used in ancient manuscripts. The term was used by the early Christians to refer to the special love for God and God's love for humanity, as well as the self-sacrificing love they believed all should have for each other.
A gape has been expounded on by many Christian writers in a specifically Christian context. In this Christian context, agape has been defined as an intentional response to promote well-being when responding to that which has generated ill-being (Thomas Jay Oord).
