Which OS function helps manage storage space?

• A. Defragmenting disk
• B. Encrypting files
• C. Compressing files
• D. Keeping track of free space

Answer: (D)

Tracking free space is what enables the system to manage storage effectively. The operating system maintains metadata that records which disk blocks are free and which are in use, often using structures like bitmaps or free-block lists. This bookkeeping lets the OS allocate space for new data, reclaim space when files are deleted, and report how much free capacity remains. It’s the core function that coordinates how data gets stored across the disk.

Defragmenting the disk rearranges existing data to improve contiguous access, which boosts performance but doesn’t by itself manage overall free space. Encrypting files adds security and changes the data representation, but it doesn’t provide the system-wide accounting of available storage. Compressing files reduces how much space individual files occupy, but space management at the system level still hinges on knowing which blocks are free and available, which is why keeping track of free space is the best fit.