I am new to puppet and while going through puppet courses, I found one person using 'puppet agent -t' command to configure an agent node while in another course, the instructor using 'puppet apply' command.
What is the difference between these two commands?
These are:
puppet apply - applies or "executes" Puppet code on the local machine.puppet agent -t also sometimes written puppet agent --test - calls the Puppet Agent to retrieve a catalog (compiled Puppet code) from a Puppet Master, and then applies it locally and immediately.Note that -t is badly-named, and it may originally have been intended for "testing" but in fact it is not a "test" mode at all, but will make changes to your machine.
See also puppet agent --noop for the real "test" (dry-run) mode.