The word 天上 is formed through the direct spatial combination of its two component characters: 天 (tiān), meaning "sky" or "heaven", and 上 (shàng), meaning "above" or "on". Conceptually, one character establishes the primary realm or object (the sky), and the second character is placed in relation to it, denoting the area that is upon or above that realm. It visually and logically creates the idea of "the space above in the sky" or "heavenward", building a compound meaning from a simple positional relationship.