Graffiti refers to a form of art consisting of words or drawings scrawled across public buildings, monuments and other structures. In Egypt you can find graffiti scrawled by Roman soldiers on ancient monuments alongside those scrawled or drawn by Napoleon's army. American soldiers in the course of several wars left graffiti indicating that "Kilroy was here" in Europe, Japan, Korea, Vietnam and elsewhere. Modern graffiti artists seem to prefer the medium of the spray paint can. The more difficult the accessibility and the more public the location, the more prestige there is associated with graffiti placed there.
Most people consider graffiti to be a deplorable form of vandalism, an insult to decent and law-abiding citizens and most graffiti are rubbish but just a few are good.