secondary storage

secondary storage

1. optical

   • Data is recorded by making marks in a pattern that can be read back with the aid of light, usually a beam of laser light precisely focused on a spinning optical disc. An older example of optical storage that does not require the use of computers, is microform.
   • CD-ROM. Compact Disc - Read-Only Memory (CD-ROM) discs can hold around 800MB of data. ... DVD-ROM. Digital Versatile Disc - Read-Only Memory (DVD-ROM) discs can hold around 4.7GB of data (a dual-layer DVD can hold twice that). ... Blu-Ray. Blu-Ray disks are a recent replacement for DVDs. ... DVD-RAM.
   • example devices
     • bluray
     • DVD
     • CD

2. magnetic

   • Magnetic storage or magnetic recording is the storage of data on a magnetised medium. Magnetic storage uses different patterns of magnetisation in a magnetisable material to store data and is a form of non-volatile memory
   • Magnetic storage media and devices store data in the form of tiny magnetised dots. ... Hard-drives have a very large storage capacity (up to 1TB). ... A hard-drive built into the case of a computer is known as 'fixed'.
   • example devices
     • hard disc drive
     • magnetic tape
     • floppy disc drive

3. solid state

   • example devices
     • SSD
     • USB memory stick
   • example
     • <- this one is joint.
   • Solid-state storage (SSS) is a type of computer storage media made from silicon microchips. SSS stores data electronically instead of magnetically, as spinning hard disk drives (HDDs) or magnetic oxide tape do.