disk compression

Technique, based on data compression, that makes hard disks appear to have more storage capacity than is normally available. If the data stored on a disk can be compressed to occupy half the original amount of disk space, it will appear that the disk is twice its original size. The processes of compression (to store data) and decompression (so that data can be used) are hidden from the user by the software. The need for disk compression software has reduced, as the availability of large capacity hard disks has increased and as their prices have fallen.