有咩係Primary memory和Secondary memory?

Primary Memory is "RAM", which is present in the board itself.
Secondary Memory is "Harddisk", which is a pheripheral device.
We know that RAM is faster than hard disk and so we are using it as the main memory for performing operations and hard disks are just used to store data.

The access time of RAM is around 5 nano seconds, but access time of Hard disk is around 10 milli seconds.

As you know when ever a product is very good then the price will also be very high. The price of RAM (Primary memory) is very high than that of Secondary memory. And hence it used less.


圖片參考：http://hk.yimg.com/i/icon/16/1.gif
Detailed discussion about primary and secondary memory see below:
http://in.answers.yahoo.com/question/index?qid=20061208035749AAAVRq1

Primary memory 快過 secondary memory!

Primary memory ; CPU 入面既cache, registry

secondary memory : CDR, Floppy....