Exporting is the exposure of some constructs for use outside of a unit. In some runtimes exporting is typically implicit and anything that is not private is exposed, or there may be some combination depending on the granularity involved.
What is exported reflects the exposed surface area/interface, and therefore it may be a key enabler in defining an abstraction.
In lower level systems exporting may amount to a combination of altering the means by which the construct is addressed (i.e. not being able to rely on static addressing) and complementary registration for use by linkage and security related obfuscation of PIE data.
Exports can be assigned to the exports value of the
module object:
module.exports = ...The export linkage flag (such as associated with a
function) enables external use of the flagged code.