In the psychological literature, a distinction is often made between two types of love.[1] Hatfield & Walster define:[1]
passionate love as "a state of intense longing for union with another. Reciprocated love (union with the other) is associated with fulfillment and ecstasy; unrequited love (separation) is associated with emptiness, anxiety, or despair"[1]
companionate love as "the affection we feel for those with whom our lives are deeply entwined."[1]
Companionate love is commonly called "attachment"[6][9][5] (sometimes in relation to attachment theory,[10] but not always)[9] or compared to strong liking,[2] friendship love[2] or Storge.[2]
Passionate and companionate love follow different mechanics,[2] and evolutionary theories suggest they exist for different purposes.[3][5] Passionate love is usually only present in the early stage of a relationship and then fades,[6] and companionate love often follows after.[4][8] Both passionate and companionate love contribute to relationship satisfaction.[2]
Passionate and companionate love are further distinguished from a third type of love, compassionate love, which is specifically focused on caring about others.[2]