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.
Electronic data storage is storage which 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. Electromagnetic data may be stored in either an analog or digital format on a variety of media. This type of data is considered to be electronically encoded data, whether or not it is electronically stored in a semiconductor device, for it is certain that a semiconductor device was used to record it on its medium. Most electronically processed data storage media (including some forms of computer data storage) are considered permanent (non-volatile) storage, that is, the data will remain stored when power is removed from the device. In contrast, most electronically stored information within most types of semiconductor (computer chips) microcircuits are volatile memory, for it vanishes if power is removed.
With the exception of barcodes and OCR data, electronic data storage is easier to revise and may be more cost effective than alternative methods due to smaller physical space requirements and the ease of replacing (rewriting) data on the same medium. However, the durability of methods such as printed data is still superior to that of most electronic storage media. The durability limitations may be overcome with the ease of duplicating (backing-up) electronic data.
Hard disk drive
 Interior of a hard disk drive | |
| Date invented | 24 December 1954\ |
|---|---|
| Invented by | An IBM team led by Rey Johnson |
A hard disk drive (HDD; also hard drive or hard disk) is a non-volatile, random access digital data storage device. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the platters.
Introduced by IBM in 1956, hard disk drives have decreased in cost and physical size over the years while dramatically increasing in capacity. Hard disk drives have been the dominant device for secondary storage of data in general purpose computers since the early 1960s. They have maintained this position because advances in their recording density have kept pace with the requirements for secondary storage.[3] Today's HDDs operate on high-speed serial interfaces; i.e., serial ATA (SATA) or serial attached SCSI (SAS).
Memory card
A memory card or flash card is an electronic flash memory data storage device used for storing digital information. They are commonly used in many electronic devices, including digital cameras, mobile phones, laptop computers, MP3 players, and video game consoles. They are small, re-recordable, and able to retain data without power.
USB flash drive
USB flash drives are often used for the same purposes for which floppy disks or CD-ROMs were used. They are smaller, faster, have thousands of times more capacity, and are more durable and reliable because of their lack of moving parts. Until approximately 2005, most desktop and laptop computers were supplied with floppy disk drives, but floppy disk drives have been abandoned in favor of USB ports.
USB Flash drives use the USB mass storage standard, supported natively by modern operating systems such as Linux, Mac OS X, Windows, and other Unix-like systems. USB drives with USB 2.0 support can store more data and transfer faster than a much larger optical disc drives like CD-RW or DVD-RW drives and can be read by many other systems such as the Xbox 360, PlayStation 3, DVD players and in some upcoming mobile smartphones.
Nothing moves mechanically in a flash drive; the term drive persists because computers read and write flash-drive data using the same system commands as for a mechanical disk drive, with the storage appearing to the computer operating system and user interface as just another drive. Flash drives are very robust mechanically.
A flash drive consists of a small printed circuit board carrying the circuit elements and a USB connector, insulated electrically and protected inside a plastic, metal, or rubberized case which can be carried in a pocket or on a key chain, for example. The USB connector may be protected by a removable cap or by retracting into the body of the drive, although it is not likely to be damaged if unprotected. Most flash drives use a standard type-A USB connection allowing plugging into a port on a personal computer, but drives for other interfaces also exist.
USB flash drives draw power from the computer via external USB connection. Some devices combine the functionality of a digital audio player with USB flash storage; they require a battery only when used to play music.
| Name | Acronym | Form factor | DRM |
|---|---|---|---|
| PC Card | PCMCIA | 85.6 × 54 × 3.3 mm | No |
| CompactFlash I | CF-I | 43 × 36 × 3.3 mm | No |
| CompactFlash II | CF-II | 43 × 36 × 5.5 mm | No |
| SmartMedia | SM / SMC | 45 × 37 × 0.76 mm | No |
| Memory Stick | MS | 50.0 × 21.5 × 2.8 mm | MagicGate |
| Memory Stick Duo | MSD | 31.0 × 20.0 × 1.6 mm | MagicGate |
| Memory Stick PRO Duo | MSPD | 31.0 × 20.0 × 1.6 mm | MagicGate |
| Memory Stick PRO-HG Duo | MSPDX | 31.0 × 20.0 × 1.6 mm | MagicGate |
| Memory Stick Micro M2 | M2 | 15.0 × 12.5 × 1.2 mm | MagicGate |
| Miniature Card | 37 × 45 × 3.5 mm | No | |
| Multimedia Card | MMC | 32 × 24 × 1.5 mm | No |
| Reduced Size Multimedia Card | RS-MMC | 16 × 24 × 1.5 mm | No |
| MMCmicro Card | MMCmicro | 12 × 14 × 1.1 mm | No |
| Secure Digital card | SD | 32 × 24 × 2.1 mm | CPRM |
| SxS | SxS | Unknown | |
| Universal Flash Storage | UFS | Unknown | |
| miniSD card | miniSD | 21.5 × 20 × 1.4 mm | CPRM |
| microSD card | microSD | 15 × 11 × 0.7 mm | CPRM |
| xD-Picture Card | xD | 20 × 25 × 1.7 mm | No |
| Intelligent Stick | iStick | 24 × 18 × 2.8 mm | No |
| Serial Flash Module | SFM | 45 × 15 mm | No |
| µ card | µcard | 32 × 24 × 1 mm | Unknown |
| NT Card | NT NT+ | 44 × 24 × 2.5 mm | No |
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