We store important documents to access them in the future. Computers store documents and data on storage devices like hard disks, floppy disks, and USB drives. There are two main types of storage: main storage temporarily holds current data (e.g. RAM), while backing storage permanently stores data (e.g. hard disks). Common storage devices include magnetic tapes, hard disks, floppy disks, and compact disks, which differ in terms of capacity, speed, cost, and whether they provide permanent or temporary storage.

1. Q. Why do we store our importantQ. Why do we store our important
documents?documents?
Answer:Answer: We store our importantWe store our important
document to have access to thesedocument to have access to these
documents in future.documents in future.

2. Q. Where do you think a computer storesQ. Where do you think a computer stores
documents / data?documents / data?
Answer:Answer: Computer store data in HardComputer store data in Hard
Disc, Floppy Disc and USB etc.Disc, Floppy Disc and USB etc.

3. Q. What are two types of store?Q. What are two types of store?
Answer:Answer: Two types of store are MainTwo types of store are Main
store & Backing Store.store & Backing Store.

4. Q. Which type is used to store currentQ. Which type is used to store current
data temporarily?data temporarily?
Answer:Answer: Main store is used to store dataMain store is used to store data
temporarily, e.g. RAM.temporarily, e.g. RAM.

5. Q. Which type is used to store dataQ. Which type is used to store data
permanently?permanently?
Answer:Answer: Backing store is used to storeBacking store is used to store
data permanently, e.g. Harddata permanently, e.g. Hard
Disk.Disk.

6. Dear students, today we shallDear students, today we shall
study about the storage devicesstudy about the storage devices

7. Answer:Answer: These are hardware thatThese are hardware that
record and retrieves items torecord and retrieves items to
and from a storage medium.and from a storage medium.
Q. Define storage device:Q. Define storage device:
STORAGE DEVICESSTORAGE DEVICES

8. Answer: Some common storage devicesAnswer: Some common storage devices
are Magnetic tape, Hard Disk,are Magnetic tape, Hard Disk,
Floppy Disk, Compact Disk etc.Floppy Disk, Compact Disk etc.
Q. Can you name some storageQ. Can you name some storage
device?device?
STORAGE DEVICESSTORAGE DEVICES

9. STORAGE DEVICESSTORAGE DEVICES
Q. What are the properties of storageQ. What are the properties of storage
devices?devices?
Answer:Answer:
 Storage devices are permanent storageStorage devices are permanent storage
 They are less expensive than main memoryThey are less expensive than main memory
(RAM)(RAM)
 They are slower than main memory (RAM)They are slower than main memory (RAM)

10. STORAGE DEVICESSTORAGE DEVICES
Now we shall study these storage devicesNow we shall study these storage devices
one by oneone by one

11. Magnetic TapeMagnetic Tape
Stores data magnetically likeStores data magnetically like
audio cassetteaudio cassette
Possesses Large capacityPossesses Large capacity
Cheap storage deviceCheap storage device
It uses serial access methodIt uses serial access method
to store data.to store data.
Runs at slow speedRuns at slow speed
Used as a backup deviceUsed as a backup device

12. Magnetic DiskMagnetic Disk
The disk inside is round in shapeThe disk inside is round in shape
It uses random access method toIt uses random access method to
read or write data.read or write data.
Faster than magnetic tapeFaster than magnetic tape
TypesTypes
Floppy DiskFloppy Disk
Hard DiskHard Disk

13. Floppy DiskFloppy Disk
It is small flexible disk kept inIt is small flexible disk kept in
plastic coverplastic cover
It has low capacityIt has low capacity
It is faster speed than tapesIt is faster speed than tapes
It is portableIt is portable
It is cheapIt is cheap
Used to transfer a small filesUsed to transfer a small files
from one computer to anotherfrom one computer to another

14. Q. Before the introduction of USB, what device isQ. Before the introduction of USB, what device is
used to transfer a file from one computer toused to transfer a file from one computer to
another?another?
Answer:Answer: Before the introduction of USB Floppy Disk isBefore the introduction of USB Floppy Disk is
used to transfer files from one computer toused to transfer files from one computer to
another.another.
Q. Why it is called “floppy” disk?Q. Why it is called “floppy” disk?
Answer:Answer: It is flexible so it is called floppy disk.It is flexible so it is called floppy disk.

15. Hard DiskHard Disk
Made up of a Metal diskMade up of a Metal disk
inside sealed containerinside sealed container
Large capacityLarge capacity
Fastest speedFastest speed
Fixed inside computerFixed inside computer
Used to store large amountUsed to store large amount
of data and softwareof data and software
Also called Winchester DiskAlso called Winchester Disk

16. Compact DiskCompact Disk
Thin metal disk in hard plasticThin metal disk in hard plastic
coatingcoating
Larger capacity than floppyLarger capacity than floppy
diskdisk
Faster speed than floppy diskFaster speed than floppy disk
Used for software distributionUsed for software distribution
is called “compact” diskis called “compact” disk
because it is very thinbecause it is very thin

17. Activity 1Activity 1
Q. Arrange these storage devices inQ. Arrange these storage devices in
order from smallest to largest onorder from smallest to largest on
the bases of Storage capacity/size.the bases of Storage capacity/size.
Answer:Answer:
1.1.Floppy diskFloppy disk
2.2.Compact diskCompact disk
3.3.Magnetic tapeMagnetic tape
4.4.Hard diskHard disk

18. Activity 1Activity 1
Q. Put these storage devices in orderQ. Put these storage devices in order
from smallest to largest on thefrom smallest to largest on the
bases of Access speedbases of Access speed
Answer:Answer:
1.1.Magnetic tapeMagnetic tape
2.2.Floppy diskFloppy disk
3.3.Compact diskCompact disk
4.4.Hard diskHard disk

19. Activity 1Activity 1
Q. Put these storage devices in orderQ. Put these storage devices in order
from smallest to largest on thefrom smallest to largest on the
bases of Cost per gigabytebases of Cost per gigabyte
Answer:Answer:
1.1. Magnetic tapeMagnetic tape
2.2. Hard diskHard disk
3.3. Compact diskCompact disk
4.4. Floppy DiskFloppy Disk

20. Activity 2Activity 2
Q. Which device is suitable to store the programsQ. Which device is suitable to store the programs
and applications which run on computer?and applications which run on computer?
Answer:Answer: Hard disk is suitable to store theHard disk is suitable to store the
programs and applications which run onprograms and applications which run on
computer.computer.
Q. Which device is suitable to store MS OfficeQ. Which device is suitable to store MS Office
software setup?software setup?
Answer:Answer: Compact disk is suitable to store theCompact disk is suitable to store the
programs and applications which run onprograms and applications which run on
computer.computer.

21. Activity 2Activity 2
Q. Which device is suitable to store a file of 800Q. Which device is suitable to store a file of 800
kilobytes?kilobytes?
Answer:Answer: Floppy disk is suitable to store theFloppy disk is suitable to store the
programs and applications which run onprograms and applications which run on
computer.computer.
Q. Which device is suitable to store back up copy ofQ. Which device is suitable to store back up copy of
the data of schoolthe data of school network?network?
Answer:Answer: Magnetic tape is suitable to store theMagnetic tape is suitable to store the
programs and applications which run onprograms and applications which run on
computer.computer.

22. HOME WORKHOME WORK
Tasks 1,2 and 3Tasks 1,2 and 3 on page 34 of your book.on page 34 of your book.
Submission date:Submission date: 1212thth
February, 2011February, 2011

23. CONCLUSIONCONCLUSION
Today we have learned how computer storeToday we have learned how computer store
data, in next lesson we will learn some moredata, in next lesson we will learn some more
capabilities of computer and compare in withcapabilities of computer and compare in with
manual systems.manual systems.