What does a follow focus do?

Related questions

1. What is a cameraman called?
2. What is a follow focus for with DSLR?
3. Is follow focus necessary?
4. What does pulling focus mean?
5. What is follow focus on Iphone?
6. What are the duties of the gaffer?
7. Why is it called rack focus?
8. What does a 1st AC do?
9. Is manual focus better than autofocus?
10. Do filmmakers use autofocus?

Tags

1. #device
2. #control
3. #necessary
4. #allows
5. #video
6. #camera
7. #operator
8. #focus
9. #precise
10. #having
11. #changing
12. #follow
13. #shooting
14. #strictly
15. #called
16. #efficient