In information technology, a backup, or the process of backing up, refers to the copying and archiving of computer data so it may be used to restore the original after a data lossevent. The verb form is to back up in two words, whereas the noun is backup. Backups have two distinct purposes. The primary purpose is to recover data after its loss, be it by data deletion or corruption. Data loss can be a common experience of computer users. In a survey found that 66% of respondents had lost files on their home PC. The secondary purpose of back ups is to recover data from an earlier time, according to a user-defined data retention policy, typically configured within a backup application for how long copies of data are required. Though backups popularly represent a simple form of disaster recovery, and should be part of a disaster recovery plan, by themselves, backups should not alone be considered disaster recovery.
A data storage device is a device for recording (storing) information (data). Recording can be done using virtually any form of energy, spanning from manual muscle power in handwriting, to acoustic vibrations in phonographic recording, to electromagnetic energy modulating magnetic tape and optical discs.
A storage device may hold information, process information, or both. A device that only holds information is a recording medium. Devices that process information (data storage equipment) may either access a separate portable (removable) recording medium or a permanent component to store and retrieve data.
Electronic data storage requires electrical power to store and retrieve that data. Most storage devices that do not require vision and a brain to read data fall into this category.