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 is accomplished by 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.
NVM Express devices are chiefly available in the form of standard-sized PCI Express expansion cards and as 2.5-inch form-factor devices that provide a four-lane PCI Express interface through the U.2 connector (formerly known as SFF-8639). However, there are also storage devices using SATA Express and the M.2 specification which support NVM Express as the logical device interface. These have recently become a popular use-case for NVMe and are quickly becoming the dominant form of solid-state storage for desktops and laptops alike.