Memory of a computer and its types

 Memory of a computer - 

                                Memory of a computer is the storage place of a computer where computer store data and information. It is divided into two parts-

1)Primary Memory-

                        The memory built inside the computer in chip form is called primary memory. It  is a part of the CPU. Instructions has to be stored in the primary memory in order to make it work automatically, though the access time is less and it is measured in megahertz. This type of memory is very fast but the capacity of this type of memory is limited. There are two types of primary memory. They are-

a) RAM and 

b)ROM.

(RAM, ROM of  primary memory)

a)RAM(Random Access Memory) - 

                                                RAM is also known as read/write memory i.e. we can read  information from it as well as also write on it. RAM  is volatile i.e. its contents are lost when the power supply is switched off. RAM  is of two types -

1)DRAM(Dynamic Random Access Memory),

2)SRAM(Static Random Access Memory).

(Image of RAM)

b) ROM(Read Only Memory)-

                                        The ROM are pre-programmed for the benefit of the user, hence we are not allowed to write anything to it. It's like a text book, we can only read from it, but we cannot write into it. ROM are basically non-volatile, i.e. its contents are not lost, when the power supply is switched off.

(Image of ROM)

2) Secondary Memory - 

                                 Secondary memory is also called secondary storage device. We can store our data permanently in the secondary memory. As compared to primary memory it is not so fast. Thus it takes slightly more time to review data from the secondary memory devices. The components of secondary memory devices are-

1) Compact disk and

2) Hard disk.

These disk can vary in terms of their storage capacity. There are two major categories of disks-

1) Pen drive-data storage device,

2) External hard disk drive-data storage device.

(secondary memory)

1)Compact Disks and DVD Disk - 

                                                It is the latest high reliability low cost memory media. It uses the technology to read and write the information. The major advantage of CD is that it is portable and the data reliability is very high. Example- In CD almost  640MB information can be stored and DVD 4.3GB data storage as well as dual layer DVD 8.3GB data storage capacity.

(DVD)

2) Hard Disk -              

                    A hard disks is similar to floppy disk in which it store data and information. It is much larger than and much faster than floppy disk. The capacity of hard disk is measured in megabytes (MB) and gigabytes(GB)  which comes in various sizes. 40GB, 120GB, 500GB, 1GB, 2GB and  many more. The hard disk is commonly used as secondary storage device for personal computer and  mini frame computer. Hard disk is a smooth metal plates coated by both side with a thin layer of magnetic materials. The data stored in hard disk is not affected by the turn off  of PC it remains there unless we instruct the PC to remove it or the hard disk is damaged.    

                

(Hard Disk)

(The above information is authentic as per my knowledge)