Compression, compaction, and thin provisioning are ONTAP storage efficiency techniques. Compression reduces the physical space consumed by compressible data blocks. Compaction packs small I/O writes more efficiently into storage blocks to reduce wasted space, especially on AFF systems. Thin provisioning presents logical capacity to clients without reserving all physical capacity up front, allowing storage to be consumed as data is actually written. Encryption protects data confidentiality but is not a capacity-saving technology. Advanced Drive Partitioning improves disk utilization by partitioning drives for root and data usage, but it is a platform layout mechanism rather than the standard ONTAP data-reduction efficiency listed with compression and compaction. The NCSE interpretation must distinguish capacity efficiency from security and hardware layout features. The three selected options are the technologies that reduce or optimize consumed capacity at the volume or aggregate layer. References/topics: ONTAP storage efficiencies, inline compression, data compaction, thin provisioning, AFF efficiency defaults, and capacity management.