Street Art and Graffiti! There is always a confusion about those two terms but here we are to make it clear for you guys! Just have on your mind that Street art is unofficial and independent visual art created in public locations for public visibility, whereas graffiti is marks, scratching or drawings made on a surface on a public place.
Graffiti can take the form of art, drawings or words. Just think that there are some people who do murals of graffiti rather than just writing one mark in a location.
Bansky is maybe the combination of those two terms! He is worldwide known as a street and graffiti artist.
Blu is another well known, Italian street and graffiti artist! Watch this nice wall-painted animation, an amazing piece of art he made!

Sources:
wikipedia
kids.kiddle.co