Literally, "heap." The five skandhas, or aggregates, are the five basic transformations that perceptions undergo when an object is perceived. They are form, feeling, conception, formation, and consciousness. In the confused state, we cling to one or another aspect of these five as a concrete self. When the skandhas are actually seen for what they are, no self is found in them, either singly or taken together. Moreover, one does not find any individual apart from them. In vajrayana, they are correlated to the five buddhas of the mandala.
1) Form Aggregate, gzugs kyi phung po, rupa skandha
2) Feeling Aggregate, tshor ba'i phung po, vedana skandha
3) Conception Aggregate, 'du shes kyi phung po samjna skandha
4) Formation Aggregate, 'du bye kyi phung po, samskara skandha
5) Consciousness Aggregate, rnam par shes pa'i phung po, vijnana skandha