Computer Memory

Memory

Memory is the storage location where we can store data, each memory location have an address.

Classification of Memory

I.Based on Storage medium


1. Semiconductor memory

  Stores data in semiconductors.
eg: ROM, RAM

2. Magnetic memory

  Stores data in magnetic particle.
eg; Hard disk, Floppy disk

3. Optical memory 


Stores data in optical media.


eg; CD, DVD

II. Based on working


1. Primary memory

It is also known as main memory, this memory directly communicate with the processor.
Primary memory is called volatile ie; it is temporary memory, its data will lose when the power is off.
It is used for storing current running data, ie; for eg; if we drawing a picture in Paint, its current data will be in primary memory until we save it to hard disk. Increasing the size of this memory increases computing speed.
eg;RAM, ROM


2.Secondary memory

The memory communicate through primary memory is called secondary memory, it is non-volatile ie; it is used for permanent data storage.
eg; Hard disk, Floppy disk, CD, DVD etc.

Comparison between Primary and Secondary memory

Primary memory                                                   Secondary memory

1. Volatile                                                                Non-volatile
2. Temporary storage                                               Permanent storage
3. Low capasity                                                       High capasity
4. High speed                                                          Medium speed

Comparison between RAM (Random Access Memory) and ROM (Read Only Memory)

RAM                                            ROM 

1. Re-writable memory                  Read only
2. Used as primary memory           Used as BIOS(Basic Input Output System, that starts up the system)
3. Volatile                                      Non-volatile
4. High capasity                             Low capacity
5. Fast                                           Slow