Computer Fundamental
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Secondary Memory



Secondary Memory

This type of memory is also known as external memory or non-volatile. It is slower than main memory. These are used for storing data/Information permanently. CPU directly does not access these memories instead they are accessed via input-output routines. Contents of secondary memories are first transferred to main memory, and then CPU can access it. For example : disk, CD-ROM, DVD etc.

Characteristic of Secondary Memory

• These are magnetic and optical memories
• It is known as backup memory
• It is non-volatile memory
• Data is permanently stored even if power is switched off
• It is used for storage of data in a computer
• Computer may run without secondary memory
• Slower than primary memories
The secondary storage devices are following types
1. Magnetic Tapes
2. Magnetic Disk (Hard disk, Floppy disk and Zip Disk)
3. Optical Disk(CD,DVD)