What terminology best describes the removal of metadata when it is no longer needed?

The term that best describes the removal of metadata when it is no longer needed is recognized as "Garbage Collection." This terminology originates from computer science and refers specifically to the process of identifying and disposing of data that is no longer in use or relevant, effectively cleaning up system resources.

Garbage Collection is important in various systems, including Salesforce and other metadata-driven environments, as it helps improve efficiency and system performance by reducing clutter and ensuring that outdated or irrelevant metadata does not take up unnecessary space or processing power. This process is crucial for maintaining a clean and efficient environment where only relevant data is active.

The other options, such as Data Cleansing, System Maintenance, and Destructive Changes, encompass different aspects of data management. Data Cleansing refers more broadly to the improvement of data quality rather than the specific removal of unneeded metadata. System Maintenance generally involves routine tasks to ensure systems operate smoothly, which might include updates or monitoring but not specifically focused on metadata removal. Destructive Changes usually imply the intentional removal or alteration of existing data rather than the automated or systematic process of cleaning up unnecessary metadata.

Thus, the concept of Garbage Collection directly aligns with effectively managing and removing unneeded metadata to maintain the integrity and efficiency of the system.