Graffiti refers to writings or drawings created illicitly on walls or other surfaces in public places. While taking simple forms like words, graffiti can also include elaborate wall paintings. Dating back to ancient civilizations, graffiti has been a practice that continues today where paint and markers are commonly used materials. However, creating graffiti without property owner consent is typically seen as defacement and vandalism, a punishable crime in most countries.

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.