Fogo's answer 2020-09-06:
Fogo's pithy formula : Life into I Internet hanging U use
1. Process namespace .
CLONE_NEWPID. Process number .
2.IPC Namespace .
CLONE_NEWPIPC. Semaphore 、 Message queuing and shared memory .
3. Network namespace .
CLONE_NEWNET. Network devices 、 Network stack 、 Ports, etc .
4. Mount namespace .
CLONE_NEWNS. Mount point ( file system ).
5.UTS Namespace .
CLONE_NEWUTS. Host name and domain name .
6. User namespace .
CLONE_NEWUSER. Users and user groups .