Secondary storage

As a secondary memory ( lehnübersetzt from the English , secondary storage ') or "external storage" (from english, external memory ') is data storage of a computer referred to, not directly from the CPU can be accessed from, and therefore the use of the A / Output channels of the computer required.

Secondary storage is used to store data that is not in active use. It is usually slower than primary storage (main storage), but it almost always offers a higher storage capacity and is persistent ( non-volatile ).

Secondary storage systems are structured according to the technology on which the process is based:

• Optical storage
  • CD , CD-R , CD-RW , DVD , Blu-ray Disc , HD DVD , holographic storage
• Magnetic storage
  • Hard drives , magnetic tape , floppy disks , ZIP drives
• Digital storage
  • Flash memory (e.g. in USB sticks )
• Mechanical storage
  • Punched tape , punched cards

Almost all secondary storage is either magnetic or optical . A well-known exception, however, are flash memories, such as those used in e.g. B. in USB sticks or solid state drives are used.

Secondary storage is often formatted with a file system that acts as an abstraction layer for the orderly storage of files and directories and supports the storage of metadata such as the file owner, file permissions and access times.

See also

• Storage hierarchy
• Mass storage

Wiktionary: secondary  - explanations of meanings, word origins, synonyms, translations

Wiktionary: memory