What's the difference between shutdown -h and shutdown in Centos7?

Question

shutdown -h now vs shutdown now,what's the difference in Centos 7?

Answer 1

shutdown now traditionally takes the system down to runlevel 1 (single user mode).

shutdown -h now will take the system down to runlevel 0 (system halt). This may or may not shut the power off to the server. It depends on the system you're running it on.

That being said, when I experimented on an AWS CentOS 7 instance, both commands shut the server off. Which leads me to conclude that either command may differ depending on what OS you're using and if it's built on bare metal or virtualized.

This post has a more detailed answer https://askubuntu.com/questions/578144/why-doesnt-running-sudo-shutdown-now-shut-down