# data[].attributes.body
these are a form of electrically erasable programable read only memory. they are used for storing photos on cameras. they are very compact but have a lower storage capacity than hard disks

# data[].attributes.body
Can store several gb of data. are aconnected to a computer throght a usb port. they are used to transport files between computers and as a security device.They are very compact and they are not affected by magnetic fields. but they are easy to lose and need to be carefully removed from the computer

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These disks are a rewritable media and can be written over several times. They are used to record television programmes

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These disks are recordable ONCE only. They are used to store data to be kept for later use or to be transferred to another computer.

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These disks are read-only-memory and this means they cannot be written over and can only be read. The data is stored as a series of pits and lands and they are read from the center outwards in a spiral.

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Data stored in the RAM is temporary while internal or external Secondary Storage Devices save data permanently. The more bytes the larger the size of the memory and its capacity.

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They don`t rely on magnetic propeties, they store data by controlling the movement of electrons within NAND chips. However they sometimes use EEPROM tecnology but they use NOR chips wich makes them faster. these are very expensive but more useful.
the majority of solid state storage devices use NAND tecnology. They are distinguished by flash and EEPROM.

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They are optical storage devices. Laser light is used to read and write data on the disk. The difference between the DVDs and the CDs is the dual-layering which increases the storage capacity.

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Many computer systems come with USB connectors only and no DVD or CD drive. some ways to store music are on hard disk drive systems, MP3s, using the "cloud" and by streaming from the internet.

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They are read and written to by a read/write head. Data is read from the tape using serial access. It is useless in a real time or online application because the data access is slow.

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Serial access: used on magnetic tape systems, it is slow because it  is necessary to start at the beginning and access each file until the record needed is found. When the master file needs to be updated, a transeption file with all the new data becomes the new master file.

Direct access: used with magnetic disks, optical and solid state media. Using the key field the computer calculates where data is stored and access it directly and quickly. Old data is overwritten by new data when updating. It is used in real time operations and online systems.

# data[].attributes.body
Another example of optical storage media but they are different to DVDs. they come with a secure encryption system. They have very large storage capacity. but they have encryption problems.

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Same as fixed hard disk drives but they are connected to the computer via USB port and can store more data.

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Safeguard against loss of data (hardware failure, file corruption or overwriting files).

Hackers could cause corruption and data loss.

To use duplicates elsewhere to protect original files.

Virus attatchment to original file.

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They are the main method used for data storage. It allows data to be written or read from the disk surface.The hard disk usually stores the disk operating system which also helps to storage data.

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"Backing up" means to copy data or files to a different medium in case the secondary storage device has issues. This is sometimes done automatically.
Backups are stored in a different place than the main server in case of fire.

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Alasia, Arbetman, Clark, Delannoy, Hansing, Marrocco, Solorzano, Podesta

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Uses are very different to CDs and DVDs. They use a number of concentric tracks, which it allows simultaneous read an write operations. They also have great longevity. Can be written to and read from many times. they have a long life, and very large capacity. but they are expensive.

# data[].attributes.body
This depends on the magnetic properties of certain materials. It is located on the surface of a disk that can be magnetised to represent a 1 or a 0.Hard disk drives can have more than one disk called platters.