I see that the path variable is defined in my .profile file, and not in my .bashrc file. I have not changed either file. When using a shell initiated from the terminal icon on my desktop GUI, I can still echo $PATH.
So, what I am asking is, is the reason I can do this because, when I clicked the icon on my desktop for the terminal, a login shell process forked to the non-login shell I am interacting with, so the non-login shell I am using inherited the environment of the login shell, which was sourced from .profile? Is this understanding correct?