A sanctum is the holiest place inside a holy building such as a temple, mosque or a private place or room where someone is never interrupted. Sanctuary means a official protection given to someone by a place that is safe for them or a place where people who are in danger from other people can go to be safe. one another sanctuary is a place where birds or animals are protected and allowed to live freely.

A sanctum can be some sacred inner space inside a church, or some private place, away from distractions. "He considered his study room his sanctum - a place where he could read, relaxed and away from the cares of the world." A sanctuary is usually used to mean some area where something or someone is safe against some threat. A wildlife sanctuary is an area where wild animals can live without being hunted by humans. A church in olden times was considered a sanctuary from the law. If a person managed to get inside the church, the government officials couldn't go in and get him.