Complexes are basically a collection of prepared and secured modules that have been specialised.
Teleport complexes are very similar to shuttle ports in their function, but utilise advanced ISR technology. They create a field so that they can transport a localised volume through space to arrive at the complex. As this is not an exact science due to quantum uncertainties and nodal decay they cannot be used to export items only import them.
They have two primary advantages; the first is that they can be used to import items from any other undocked position within the same system. The second is that they can be used to import items even if the starbase or outpost is currently locked in combat. They cannot however pick up items from another position if that is itself locked in combat.