Love comes in eight flavors, built from just three ingredients

Robert Sternberg proposed that love is made of three components: intimacy, passion, and commitment. Different combinations produce different kinds of love — passion alone is infatuation, intimacy and commitment without passion is companionate love, and all three together is consummate love. The theory explains why a relationship can feel like love but still be missing something.

— Robert J. Sternberg, A Triangular Theory of Love — Psychological Review, vol. 93, 1986