Some "SSH & exec" Questions

hi h ave some questions about SSH and exec php function i have Cloudlinux and i am using CageFS with normal php ea-* 1 - what the difference between ( Normal Shell & Jailed Shell ) without CageFS ? 2 - what the difference between ( Normal Shell & Jailed Shell ) with CageFS: note that i am using CageFS ? 3 - if i am using "exec" php function, is it safe with CageFS and ( Normal Shell & Jailed Shell ) ? 4 - if i am using "shell_exec" php function, is it safe with CageFS and ( Normal Shell & Jailed Shell ) ? thanks