Memory and Memory units

 

Memory or the storage unit in computer

 

As we knows that any event we remain (store) in our mind.like this computer ,store any thing in its memory.

It is basically of to types

1-primary memory

2-secondory memory

 

 

1-primary memory

Ram (random access memory)

It is volatile memory   means if   computer turned off ,all data in RAM will be  lost

(Vanished). We can random select and use any location of this memory to directly store and retrieve data and instruction. It is also known as read/ write  memory  because information can be read from a ram chip and can also written into it.

 

Rom (read only memory):-

It is nonvolatile memory means if computer turned off, data will be remain. We can only read the information from rom .We cannot write in it.

PROM(PROGRAMMABLE READ ONLY MEMORY)

It is like ROM but manufactures can write one time on this memory

 

EPROM (ERASABLE PROGRAMMABLE READ ONLY MEMORY)

Computer manufacturer can write the program (one or more time) in this memory.

Cache memory:-

It is a special type of high speed memory which is used to increase the speed of processing at a rapid rate it is situated between the CPU and main memory (RAM) .It is also a temporary (volatile) memory.

2 –secondary memory

 It is very expensive so the additional memory is used to increase storage capacity .it is nonvolatile memory. Such as HARDDISK, FLOPPY, CD ROM DVD PENDRIVE etc.

Memory unit –

The smallest unit of memory is bit but generally we measure it in byte which is equal 8 bit.

1 byte=8 bit

 1kilobyte (kb) =1024byte

1 megabyte (mb) =1024 kb

1 gigabyte (Gb)= 1TB