Types and Function of Secondary Storage

Secondary storage is another alternative storage to keep your work and documents. It is very useful to store programs and data for future use. It is installed externally. It is non-volatile.It will store the information until it is erased.

Secondary storage can be divided into three main types : 


Magnetic Medium: Magnetic Medium is a non-volatile storage medium. Magnetic disks use magnetic particles to store items such as data ,instructions and information in disk's surface.  
  
The examples of magnetic storage are :
Magnetic disk such as floppy disk, hard disk, zip disk.

Hard disk

Magnetic tape such as video cassette , tape.  

    

 Floppy Disk

Zip disk

                      

                            Tape

         

             Video cassette

Optical Medium : Optical medium is a non-volatile storage media that consists of a flat , round , portable disc made of metal and plastic that is written and read by a laser. 
  
These following forms are often commonly used : 

1. CD , DVD and BD :  read only storage used for distribution of digital information such as music ,video and computer programs.
2. CD-R and DVD-R : write once storage , the data cannot be erased or written over once it is saved.
3. CD-RW , DVD-RW and DVD RAM : it allows data that have been saved to be erased and rewritten.                

 Flash memory : Flash memory is a solid-state media which they consist entirely of electronic components and contains no moving parts.  

There are two type of flash memory :

Memory card : It is used with digital cellular phones ,MP3 players ,digital video cameras and other portable digital devices. 

                  

                      Memory stick

Multi Media card

Flash Drive : It also called USB drives ,thumb drives or pendrives.

                                                                                        

Pendrive