It is important to understand that people have been painting and marking walls since the earliest of times. Cave dwellers drew pictures on their walls. Graffiti and other forms of wall writing in the late twentieth century became an important method of inner-city communication. To say that graffiti has been part of our history is not to deny the legitimate complaints about defacement of public and private property, but rather to try to put it in context.
Street art originated in the late 1960s with the advent of graffiti and tagging in Philadelphia and New York. It has been developing ever since as new styles, forms and techniques are created and utilized by street artist.
Street art and graffiti overlap in many ways, but the key differences between the two lie in technique and intent.