What does the classification 'Top Secret' signify?

The classification 'Top Secret' signifies that the unauthorized disclosure of the information could cause exceptionally grave damage to national security. This level of classification is the highest and reflects the extreme sensitivity of the material involved. It is used for information that, if disclosed, could lead to significant threats or harm to national interests, making it crucial to restrict access and properly secure such information. Understanding this classification is essential for ensuring proper handling and protection of national security information, as it delineates the severity of potential consequences that come from unauthorized access.