https://en.wikipedia.org/wiki/Public_art

  Common characteristics of public art are public accessibility, public realm placement, community involvement, public process (including public funding); these works can be permanent or temporary.

  Independent art created or staged in or near the public realm (for example, graffiti, street art) lacks official or tangible public sanction has not been recognized as part of the public art genre,[8] however the popularity of some street artists have led to this notion being reconsidered by many.[9][10] Such unofficial artwork may exist on private or public property immediately adjacent to the public realm, or in natural settings but, however ubiquitous,[11][12] it sometimes falls outside the definition of public art by its absence of public process or public sanction as "bona fide" public art.[1]