[ Thanks to Andrew
Weber for this link. ]
“You may need to export variables in some circumstances
in order to use them in the child process. The export command
places the variable in the environment. The environment, which is
the list of name-value pairs like PATH, is inherited from the
parent process. The export command allows the child process to
modify the environment of the child environment only.“Locality of Variables
“Variables are local to the process where they were declared.
See Declaring Variables for more context that helps define this
blog post.“The export command with the “-p” option will show the current
variables of the environment.”