Disk status summarizes capacity for supported mounted volumes. It is intended to show storage pressure, not to classify every byte.
Used and available space
Available storage can include space macOS expects to reclaim from purgeable data. Local snapshots, file-system metadata, shared blocks, caches, and cloud optimization affect the total.
Why another display differs
Finder, System Settings, Disk Utility, and diCleaner can update at different times and categorize data differently. Compare the same volume and allow storage reporting to refresh after a large change.
Investigate low space
Use Space Analyzer for accessible folder distribution, Large & Old Files for personal candidates, Cleanup for supported generated data, and Applications for software you no longer need.
Protect system stability
Keep enough free space for updates, swap, temporary files, and application work. Avoid deleting unknown Library or system folders manually to chase a displayed category.