Graffiti is a type of deliberate marking on property, both private and public. It can take the form of pictures, drawings, words, or any decorations inscribed on any surface usually outside walls and sidewalks. When done without the property owner's consent, it constitutes illegal vandalism.
Graffiti has existed at least since the days of ancient civilizations. Graffiti originally was the term used for inscriptions, figure drawings, etc., found on the walls of ancient sepulchers or ruins, as in the Catacombs, or at Pompeii.