What purpose does the Reference bit serve in a demand paging system?

The Reference bit in a demand paging system is used to track whether a page has been accessed or not during a specific time period. When a page is accessed, its Reference bit is set to 1; otherwise, it remains 0. This information helps the operating system determine which pages are frequently used and which can be candidates for replacement during page replacement algorithms, such as the Least Recently Used (LRU) strategy. Overall, it aids in optimizing memory management and improving system performance.