Graffiti refers to writings or drawings created illicitly on walls or other surfaces. Graffiti has existed since ancient times but modern graffiti most commonly uses spray paint or markers. While graffiti was common in ancient cultures, today most countries consider unauthorized graffiti on property to be vandalism and defacement, which is a punishable crime.

1. Graffiti (plural of graffito: "a graffito", but "these graffiti") are writing or
drawings that have been scribbled, scratched, or painted illicitly on a wall or
other surface, often in a public place.[1] Graffiti range from simple written
words to elaborate wall paintings, and they have existed since ancient times,
with examples dating back to Ancient Egypt, Ancient Greece, and the Roman
Empire.[2]
In modern times, paint (particularly spray paint) and marker pens have become
the most commonly used graffiti materials. In most countries, marking or
painting property without the property owner's consent is considered defacement
and vandalism, which is a punishable crime.