Computer users store some information so that their computers can work on it almost instantly. Other information is stored only so that it can be transported from one computer to another. Government agencies and large corporations put vast amounts of reference and financial data into long-term storage. Collections of such data are known as archives.
Companies commonly use data storage as a back-up.
A company duplicates valuable data and then stores the copy away from the company's place of business. The most common storage devices are magnetic units called floppy disks and hard disks. Floppy disks are removable and are therefore used to transport data. Most hard disks are permanently installed inside computers. Larger optical disks store archival material.