Generative art refers to art that in whole or in part has been created with the use of an autonomous system. An autonomous system in this context is generally one that is non-human and can independently determine features of an artwork that would otherwise require decisions made directly by the artist. In some cases the human creator may claim that the generative system represents their own artistic idea, and in others that the system takes on the role of the creator.

Condensation Cube, plexiglas and water; Hirshhorn Museum and Sculpture Garden, begun 1965, completed 2008 by Hans Haacke
Installation view of Irrational Geometrics 2008 by Pascal Dombis
Telepresence-based installation 10.000 Moving Cities, 2016 by Marc Lee

"Generative art" often refers to algorithmic art (algorithmically determined computer generated artwork) and synthetic media (general term for any algorithmically-generated media), but artists can also make it using systems of chemistry, biology, mechanics and robotics, smart materials, manual randomization, mathematics, data mapping, symmetry, tiling, and more.