Some clarification is needed on Debian repos.

[Sthu Deus <sthu.deus@gmail.com>]

Good day.

Could You please explain, should some security testing repo be
specified for a stable + testing Debian, or stable, updates and testing
repos is all that should be enabled for the stable, testing with all
*for the repos* security fixes?

In other words, is there a security repo for testing as there is a
security repo for stable?

Also, does security team works with volatile repo and therefore can be
used for stable only system?

And one more question: If a choose a mirror from the list on Debian web
site, should there be all the repos of the distro (like stable,
testing, etc) - so that I can use the only mirror for all my needs (any
repos) OR I have to use several mirrors for diver repos (like stable
from one mirror, testing from another, stable updates from third, etc)?

Thank You for Your time.