# Data Storage in Computers (Primary and Secondary Memories)

Friends, in our previous post, we have studied how the computer takes data into the Binary System, today we shall see how the computer keeps data in various types of memory.

The greatest merit of a computer is data storage. The place where we keep data is called memory. As we already know, this memory is of two types. Those are,
1. Primary Memory (Main Memory) and
2. Secondary Memory
We can, however, compare the primary memory with our human mind. We can hold the information in the cells of our brain, and take it outside whenever the need arises. For example, we will store the address of a person called Shivani. Sometimes we will write the full address in a diary or a notebook thinking that we may forget it at any time. Then suddenly one of our relatives may ask for the address of Shivani. If we remember it in brain, we will tell it. Here the information given by the brain is called primary memory in the computer terminology.

If you don't remember the proper address and you take the address from the note book, it is termed as secondary memory. As the mind is primary, it is called primary or main memory. As we can not remember long names and numbers, we write in a diary or note book permanently. So it is called Secondary or Permanent memory.

We will study in detail the above two types of memory.

### Primary Memory

This Primary Memory is again divided into many small parts. These small parts are called memory cells. The computer will fill-up the information given by the users in these cells.

Every cell has an address. Why do we need this address ? Whenever we want to access data from the memory, we have to refer to the address of the cell where data is stored. We can also keep additional information in that cell and we can open that cell to see the data or information contained in it.

Sometimes while working on computer, the power supply may go off. Then what happens to the information ? Suppose we are storing information in the primary memory and suddenly the power goes off, we may lose all the information. To avoid this loss and safeguard the information, secondary memory is used.

#### RAM and ROM

The Primary Memory in the computer is divided into two parts. Those are,
1. Random Access Memory (RAM)
We will now discuss these two memories in detail.

When we open the computer, a system start up (we call this Booting) process begins. These contents are written in memory at the time of manufacture and they can not be changed by the user. This type of memory is called ROM (Read only Memory). This information is not lost even though the computer is switched off. As it is not lost, it is called Non Volatile Memory. This can be compared with the original thoughts and opinions that are fixed in human mind.

Now a days we have the extensions of this ROM, namely PROM and EPROM.

PROM (Programmable ROM)
As the name indicates, this type of memory can be written only once by the user or programmer. Thereafter it can not be changed by the user.

Erasable Programmable ROM (EPROM)
In this type of memory, we can modify the contents of PROM as many times as we want. This type of memory can be modified using ultraviolet light.

#### RAM (Random Access Memory)

This type of memory can be read and written by the user. It is called RAM (Random Access Memory) because any place on a chip can be selected at random and used to store programs or data. It deals with current information that we are working on. For example, if we want to add some numbers, they will be contained in RAM. Suppose again we want to type a letter, this new data can be entered into RAM. But when the computer is switched off, the information contained in this memory is completely lost. That is why it is known as "Volatile Memory". So before you switch off the computer, it is better to save the information. This RAM can be compared with the temporary thoughts and opinions in our mind which change frequently.

### Secondary Memory

In order to store the information permanently in the computer, as you know secondary memory is the solution. The information stored in the secondary memory is called Saving of Information. The computer in this case will ask for the file name. Whenever you type the name of file, it will be saved in that file permanently.

Once the files are saved, the computer will reproduce it as and when demanded. We can make changes in that file. There will be no loss of information even when power goes off. Normally, secondary memory is stored in Hard Disc, CD Rom or Pen Drive.

That's all for now friends. In our next post we shall discuss about the Data Storing Devices in Computers. Happy Reading :)

1. Teaching about Memory with Ghajini's pic :P

Thank you so much for the excellent material and good laughs. Gr8ambitionz rocks

2. When can v expect the cut off of clerk to be announced???

3. It wont b announced

4. VIRUS-a program which copies itself and multiplies
WORMS--copies and disitributes itself through networks
TROJAN--seems like performing some function,but breaches security.

5. Cut off will be said to ppl to those who din clear right???

6. Good work Ravi, nicely explained

7. expected cutoff for karnataka

8. thanks mam well explained

9. Thank you gr8.

10. when is sbi associate po result???

11. thanku GA :)

12. January end probably!

13. Plz team provide quick reference guide for sbi associate clerk asap...

14. Ya I am from lko.. My exam is on 11 evening. Can I have ur mail I'd.. So v can discuss how to prepare

15. Hey where they were asking for category in LVB application form? I think they haven't asked anything about category and job experience. Am i right?

16. Is there any problems in interview, if percentage of mark is mentioned wrongly in application forms. Any one reply me soon.

17. Hey
While filling LVB form I put Engineering/Intermediate in course type column. I am an engineering graduate. is it ok? One of my friend is telling that I should have selected graduate/Integrated graduate option

18. thanks gr8..ambiz..

19. yeah category and job experience was not asked

20. Yes it would create prob,, wat's ur percentage, and what you have entered???

21. Thanks #ravi guda

22. HI.. .i have Po interview on jan23. . .iam an 2010 pass out, i didn't mentioned any experience in the application form, will they ask why didn't you mentioned in the application?

23. wahi to yaar puch raha hun, why do u say so?

24. Excellent Teaching style i really enjoyed the topic with perfect examples i like this. thank you so much

Mene ibps clerk me apply k time pe mere last yr k hi percentage likhe the..aur ibps ne sbhi yr k aggregate bola tha...
So if it will create any prblm in future or not as i have shortlisted 4 intrw?
Please tell me if u know..

26. Who are all applied for Ibps SO?

27. please anyone tell me any tips to prepare marketing..

28. Does any one having idea about when the final result of SBI clerk will be announced??

29. Thanks team..

30. requirement for NICL 1000 VACANCY.....http://adf.ly/txOnh

31. Ibps clerk ke marks dikhayenge jo pass hai unke ya fir fail hua unke hi dikhayenge plz anybody have idea plz share

32. Malwa Gramin bank declared their posts based on CWE-RRB 3.

33. Language proficiency in PUNJABI is must

34. yeah tehy will ask alex
u better come up with good reason for that question

35. first day exam date????

36. only to not qualified they show marks i think so because they done same for po also

37. 24/01/15 mine was the first

38. 24/01/2015 starting
28/02/2015 is ending i think
i am sure of starting but ending 28 is trhe last i haerd so far

39. ssc havent given their schedule et right so why worry abt that it will be in febuary only i geuess

40. once i made same mistake on central govt job interview they just rectified and allowed me for GD and interview
so i think ibps will also allow as long as it is not problem like u passed your final exam and got degree before date thtey mention in notification

41. u can simply follow GR8 they got lot of links regarding marketing that will be more than enough

42. Primary memory is computer memory that a processor or computer accesses first or directly. For example: RAM, and Cache Memory.  Secondary memory (or secondary storage) is the slowest and cheapest form of memory. It cannot be processed directly by the CPU. Secondary memory devices include magnetic disks like hard drives and floppy disks, optical disks such as CDs and CDROMs, and magnetic tapes, which were the first forms of secondary memory.

43. from which state u hv applied???

45. Thank you

46. 24th jan starting and feb 22 ending

47. My exam on 25-01-15 ,9 am

48. Manoj in banks generally they do very strict checking, if there is variation of just .1-.2 of marks thats fine bt with bigger difference they sure ask for an answer and can take serious steps at tyms!!
All the best to you though!

49. how may questions you have attempted?

50. Try to understand exam syllabus refer good study materials find out in which section u r weak solve as many as previous question papers... to pass any exams proper prepration very important...

51. Puspa who are filled application for this examination already they are eligible.

If you want more detail check below link.

http://govtjobstuff.in/

52. k. feb 22..... prepare well... did u cleared ibps clerks?

53. didnt clear...
hmm
all the best....

54. Thanks kathir and me also cleared rrb asst and sbi clerk

55. Hello pooh u there ?

56. How are u ?

57. better
hw abt u?

58. Good.

59. hw preparation s gng on?

60. I want a help. Will u pl mail me to my id ranjithnair7@gmail.com

61. Ya gng on. Have to prepare it seriously. Urs ?

62. k...wt help?

63. me too..
i hve exams tooo...and interview
dnt knw hw to prepare

64. All the best.

65. me too yar... any way let us prepare for next exam with more effort..

66. CAN ANY ONE TELL WHAT IS AQUAINT YOURSELF BOOKLET AS IT WRITTEN IN CALL LETTER TO DOWNLOAD BUT FROM WHERE
PLS HELP

67. Thanks sir but just give d shortcut keys of computer

68. mine exam on 22 feb

69. ya gud suggestion..

70. please heilp for only engish

71. Hi im new to Bank exams../
Does this exam last a month?Mine is on 21-Feb.
My friends have their dates on 21-Jan. so bit worried. is this NORMAL ?

72. parm...my exam date is also in 21 feb..since im new to bank exams..does it take a month for exam process..since exam starts on 21-jan.
just a simple doubt

73. nice 1