I have some doubts about Tomcat and his threads. If someone could help me, i will be very grateful.

In what moment new threads are created in Tomcat when it's running?
Is there a thread pool? In case positive:
- What is the initial quantity of threads created?
- What is the stagger algorithm?
- After created, when a thread terminates (end of life, release)?
- What means o large number of threads? Many users? Many sessions? Many requests?

Thanks for any help