HARD DISK AND MEMORY

HARD DISK AND MEMORY - HOW IT WORKS

 

Memory is nothing but a Basic electronic part and stores some digital information in it. In Hard disk, the info are stored as magnetic field. Memory is simply what you are focusing on at the moment. It isn't as large as the hard drive, which can save much much more, but it is much faster which is why it is practical for only what you are currently using. You can almost think of them as short term and long term memory. Long term (hard drive) is the stuff that has been stored - archived if you will - for a time in the future, where as short term (memory) is for what you are doing right now. You can recall the information from long term and place it in your short term to use, but when you are finished, you push it right back to long term.

On a Hard Disk Drive, there is an index where the computer stores the location of saved files on the drive. When you try to access information, your processor sends a command where the HDD looks up the location of the information and then skips to that point on the disk. It then reads that information which is stored in the form of positive and negative charges, representing off and on or 0's and 1's. This code is called binary and is the language of computers.

The information it retrieves is then passed on to the memory (RAM) which is the information you are currently using. RAM is much faster than your HDD and thus is used for current tasks. While you are using the item it is stored in the RAM. When you save save something, it runs back to the HDD where it writes it on the disk and then registers where it was saved in the index. 

TYPES OF HARD DISK                                                   

Hard disks are generally accessed over one of a number of bus types, including 

ATA (IDE, EIDE) 

Serial ATA (SATA) 

SCSI

SAS

IEEE 1394

USB, and

and Fibre Channel.