Performance Art is contingent on the presence of the body. The body, site, audience and time are it’s four pillars, with corporeal action the central axis. Artists turned to the physical body and brought an ‘aliveness’, a temporality and instability to artworks. The typical understanding of Performance Art is as a solo practice with the artist’s body-as-medium at it’s core;, an embodied practice. It is the action of the body, the authenticity of an activity, that frames a work as Performance Art.
For a further information on performance art practice see Coogan’s essay What is Performance Art?