The document discusses the history and definitions of graffiti. It begins with a definition of graffiti as words or drawings on public surfaces. It then outlines the origins and evolution of modern graffiti, tracing it from political protests in 1960s US to its emergence in Philadelphia in the late 1960s. Graffiti blossomed as both an art form and culture in 1970s-80s New York, spreading from subway cars to street canvases. The document examines different types of graffiti and provides images to illustrate examples.