Data storage is the recording (storing) of information (data) in a storage medium. DNA and RNA, handwriting, phonographic recording, magnetic tape, and optical discs are all examples of storage media. 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. Barcodes and magnetic ink character recognition (MICR) are two ways of recording machine-readable data on paper.