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Data storage is the recording (storing) ofinformation (data) in astorage medium.Handwriting,phonographic recording,magnetic tape, andoptical discs are all examples of storage media. Biological molecules such asRNA andDNA are considered by some as data storage.[1][2] Recording may be accomplished with virtually any form ofenergy. Electronic data storage requires electrical power to store and retrieve data.
Data storage in a digital, machine-readable medium is sometimes calleddigital data. Computer data storage is one of the core functions of ageneral-purpose computer.Electronic documents can be stored in much less space than paperdocuments.[3]Barcodes andmagnetic ink character recognition (MICR) are two ways of recording machine-readable data on paper.
A recording medium is a physical material that holds information. Newly created information is distributed and can be stored in four storage media–print, film, magnetic, and optical–and seen or heard in four information flows–telephone, radio and TV, and the Internet[4] as well as being observed directly. Digital information is stored onelectronic media in many differentrecording formats.
Withelectronic media, the data and the recording media are sometimes referred to as "software" despite the more common use of the word to describecomputer software. With (traditional art) static media,art materials such ascrayons may be considered both equipment and medium as the wax, charcoal or chalk material from the equipment becomes part of the surface of the medium.
Some recording media may be temporary, either by design or by nature.Volatile organic compounds may be used topreserve the environment or to purposely make data expire over time. Data such assmoke signals orskywriting are temporary by nature. Depending on the volatility, agas (e.g.,atmosphere,smoke) or a liquid surface such as alake would be considered a temporary recording medium if at all.
A 2003UC Berkeley report estimated that about fiveexabytes of new information were produced in 2002 and that 92% of this data was stored on hard disk drives. This was about twice the data produced in 2000.[5] The amount of data transmitted overtelecommunications systems in 2002 was nearly 18 exabytes—three and a half times more than was recorded on non-volatile storage. Telephone calls constituted 98% of the telecommunicated information in 2002. The researchers' highest estimate for the growth rate of newly stored information (uncompressed) was more than 30% per year.
In a more limited study, theInternational Data Corporation estimated that the total amount of digital data in 2007 was 281 exabytes and that the total amount of digital data produced exceeded the global storage capacity for the first time.[6]
A 2011Science Magazine article estimated that the year 2002 was the beginning of the digital age for information storage: an age in which more information is stored on digital storage devices than on analog storage devices.[7] In 1986, approximately 1% of the world's capacity to store information was in digital format; this grew to 3% by 1993, to 25% by 2000, and to 97% by 2007. These figures correspond to less than three compressedexabytes in 1986, and 295compressed exabytes in 2007.[7] The quantity of digital storage doubled roughly every three years.[8]
It is estimated that around 120 zettabytes of data will be generated in 2023[update], an increase of 60x from 2010, and that it will increase to 181 zettabytes generated in 2025.[9]
Incomputing,mass storage refers to the storage of large amounts ofdata in apersisting andmachine-readable fashion. In general, the termmass inmass storage is used to meanlarge in relation to contemporaneous hard disk drives, but it has also been used to meanlarge relative to the size ofprimary memory as for example withfloppy disks onpersonal computers.
Devices and/or systems that have been described as mass storage includetape libraries,RAID systems, and a variety of computer drives such ashard disk drives (HDDs),magnetic tape drives,magneto-optical disc drives,optical disc drives,memory cards, andsolid-state drives (SSDs). It also includes experimental forms likeholographic memory. Mass storage includes devices withremovable and non-removable media.[10][11] It does not includerandom access memory (RAM).
There are two broad classes of mass storage: local data in devices such assmartphones orcomputers, and enterprise servers and data centers for the cloud. For local storage, SSDs are on the way to replacing HDDs. Considering the mobile segment from phones to notebooks, the majority of systems today is based onNAND Flash. As for Enterprise anddata centers, storage tiers have established using a mix ofSSD andHDD.[12]| Main articles | .svg) | |
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