Wikipedia defines graffiti as a mark deliberately left by people on public or private facilities or walls. Graffiti can be pictures or words. Graffiti without the permission of the facility owner is usually illegal or criminal.

The earliest graffiti can be traced back to Neanderthal cave paintings. In different historical periods, all kinds of words, pictures, symbols, etc. Those who are randomly smeared on specific buildings or objects, as well as the "visit here" that can be seen everywhere in modern tourist attractions, are considered graffiti.

But in fact, graffiti, as a street art, originated in America. In 1960s, Dmitry, a delivery man living in Washington, USA, scribbled his nickname "Taki 183" everywhere. This move not only made him board the The New York Times of 197 1, but also made him doodle, which originated from Greek.

Graffiti includes words, cartoon characters, political slogans and even religious and supernatural images. Graffiti painting was not noticed by the art world at first. In most cases, it is in an underground state of self-development and self-satisfaction It was not until the first half of 1980s that graffiti art surfaced and became the most popular painting style of new york School.