The word 监狱 (jiānyù), meaning "prison", is formed by combining two conceptual building blocks. The first character, 监 (jiān), carries the ancient core idea of "to oversee" or "to inspect", often associated with surveillance and control. The second, 狱 (yù), originally represented a "lawsuit" or "legal case", evolving to mean the place associated with dispute and punishment. Together, they conceptually fuse the act of watching over with the context of legal judgment and confinement, creating a compound that perfectly encapsulates the institution of a prison, a place of supervised punitive detention.