The word 出口 is formed by combining two pictographic characters into a single conceptual unit. The first character, 出, originally depicted a foot stepping out of a contained space (like a footprint leaving a cave), representing the idea of "to exit" or "to go out". It is placed above the second character, 口, which is a pictogram of an open mouth, representing an "opening" or "gateway". Their combined imagery visually and conceptually creates the notion of an exit point, a "mouth" or opening from which things go out, which logically extends to mean both a physical exit and the act of exporting goods.