The graphic expression that has taken over certain walls in Paris is a source of curiosity. Based on this observation, this dissertation explores the foundations of street art and analyses its lasting influence on the urban landscape. What kind of painting do we need in a shared public space? What is an image designed for the public good?Today, street art, which is part of our urban realities, brings colour and vitality to our towns and cities. How does street art communicate with the public? And how can we get the public involved in this decoration of the public space? It is important to identify its current status on a cultural and legal level, as well as to define its role in improving our landscape through its artistic expressions that influence our surroundings and our emotions.