Mailing the story:

The export command is one of the bash shell BUILTINS commands, which means it is part of your shell. The export command is fairly simple to use as it has straightforward syntax with only three available command options. In general, the export command marks an environment variable to be exported with any newly forked child processes and thus it allows a child process to inherit all marked variables. If you are unsure what this means read on, as this article will explain this process in more detail.