Is bootstrap a library or a framework?

Related questions

1. What does @media only screen mean?
2. What does it mean to bootstrap an application?
3. What is bootstrap grid system?
4. What can bootstrap do?
5. Is Bootstrap easy to use?
6. What is the purpose of a media query?
7. What is bootstrap Div?
8. What is MB bootstrap?
9. Which is better Flexbox or bootstrap?
10. What is a media query in CSS?

Tags

1. #customization
2. #javascript
3. #front
4. #jquery
5. #framework
6. #pretty
7. #entirely
8. #whole
9. #angular
10. #based
11. #something
12. #specific
13. #approach
14. #bootstrap
15. #library
16. #areas