Define art, How does the emergence of street art

watch video and answer few questions simple assignment 

Part 1: 0:00-44:25

video link: https://www.youtube.com/watch?v=IqVXThss1z4

questions below only complete part 1 

1. Define art.
2. How does the emergence of street art and the Internet change what constitutes as art? Cite examples from Exit Through The Gift Shop. 
3. What compels Thierry to film everything around him?
4. How does street art intersect with social commentary? Cite specific examples from the documentary.