Data storage is the recording (storing) of information (data) in a
storage medium. Handwriting, phonographic recording, magnetic tape, and
optical discs are all examples of storage media. Biological molecules such as
RNA and DNA are considered by some as data storage. Recording may be
accomplished with virtually any form of energy. Electronic data storage
requires electrical power to store and retrieve data.
Data storage in a digital, machine-readable medium is sometimes called
digital data. Computer data storage is one of the core functions of a
general-purpose computer. Electronic documents can be stored in much less
space than paper documents.