What is a Graffiti?

Graffiti (singular: graffito; the plural is used as a mass noun) is writing or drawings scribbled, scratched, or sprayed illicitly on a wall or other surface in a public place.[1] Stickers and other adhesives are not considered graffiti, apparently because they are less common. Graffiti ranges from simple written words to elaborate wall paintings, and has existed since ancient times, with examples dating back to Ancient Greece and the Roman Empire.[2] ……”Graffiti may also express underlying social and political messages and a whole genre of artistic expression is based upon spray paint graffiti styles. Within hip hop culture, graffiti has evolved alongside hip hop musicb-boying, and other elements.[3] Unrelated to hip-hop graffiti, gangs use their own form of graffiti to mark territory or to serve as an indicator of gang-related activities.”

Source: http://en.wikipedia.org/wiki/Graffiti