what is in situ

In situ is a Latin phrase that translates to "on site" or "in position." It is used to describe something that is in its original place or position, undisturbed. This term is used in various contexts, such as in physics, geology, chemistry, biology, aerospace, and archaeology. For example, in the aerospace industry, equipment on-board aircraft must be tested in situ to confirm that everything functions properly as a system. In archaeology, in situ refers to an artifact that has not been moved from its original place of deposition, which is critical to the interpretation of the artifact and the culture which formed it. In the medical field, an in situ tumor is one that is confined to its site of origin and has not invaded neighboring tissue or gone elsewhere in the body.