What is the difference between export and standard directory in OpenStudio-standards

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I have forked OpenStudio-standards to make some tweaks for my firm I wanted to copy lib/openstudio-standards/standards into my fork in order to keep it up to date with NREL/master.

Then I realized that there is also an export directory - what is the difference between these two directories? Should I updating both of them in order to keep up to date with NREL/master?