Medicine sociology How to increase the stable state of health How to use preventive medicine How to promote health

1. Chapter 8
Digital Storage
Discovering Computers 2016
Tools, Apps, Devices, and the Impact of Technology

2. Storage
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• A storage medium, also called secondary storage, is the
physical material on which a computer keeps data,
information, programs, and applications.
• Examples of storage media include Hard Disks, Solid-state
Drives (Both Of Which Can Be Internal Or External),
Memory Cards, USB Flash Drives, Optical Discs, Network
Attached Storage Devices, Magnetic Stripe Cards, Smart
Cards, RFID Tags, and NFC tags.
• Another storage option is cloud storage, which keeps
information on servers on the Internet.
• The user accesses files on cloud storage through a browser
using an app from the storage provider, the actual media on
which the files are stored are transparent to the user.

3. Storage
• A storage device is the hardware that records
and/or retrieves items to and from storage media
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Reading is the process
of transferring items
from a storage medium
into memory
Writing is the process of
transferring items from
memory to a storage
medium

4. Storage
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Figure 8-1

5. Storage
• Capacity is the number of bytes a storage medium
can hold
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Table 8-1

6. Storage
• Items on a storage medium remain intact even
when you turn off a computer or mobile device
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Pages 370 - 371
Figure 8-2

7. Storage
• Access time measures:
– The amount of time it takes a storage
device to locate an item on a storage
medium
– The time required to deliver an item
from memory to the processor
– Memory (chips) accesses items in
billionths of a second (nanoseconds).
Storage devices, by contrast, access
items in thousandths of a second
(milliseconds) or millionths of a second
(microseconds).
– Transfer rates for storage are stated in
KBps (kilobytes per second), MBps
(megabytes per second), and GBps
(gigabytes per second).
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Figure 8-3

8. Hard Drives
• A hard disk, also called a hard
disk drive (HDD) contains one or
more inflexible, circular platters
that use magnetic particles to
store data, instructions, and
information.
• Desktops and laptops often
contain at least one hard disk.
The entire hard disk is
enclosed in an airtight, sealed
case to protect it from
contamination.
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Figure 8-4

9. Hard Drives
• The storage capacity of hard disks varies and is
determined by:
– The number of platters the hard disk contains
– Whether the disk uses longitudinal or perpendicular
recording
– Density
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10. Hard Drives
• Formatting is the process of dividing the disk into tracks
and sectors
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Figure 8-5

11. Hard Drives
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in whole or in part.
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Figure 8-6

12. SSD (solid state drive)
• An SSD (solid state drive) is a flash memory storage
device that contains its own processor to manage its
storage
• An SSD (solid state drive) has several advantages over
traditional (magnetic) hard disks:
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in whole or in part.
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Pages 376 - 378
Faster access
times
Faster transfer
rates
Quieter
operation
More durable Lighter weight
Less power
consumption
Less heat
generation
Longer life
Defragmentation
not required

13. SSD (solid state drive)
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in whole or in part.
13

14. Hard Drives
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Pages 378 - 379
Figure 8-9
• An external hard disk is a separate freestanding
storage device that connects with a cable to a USB
port or other port on a computer or mobile device

15. Portable Flash Memory Storage
• Sometimes called a thumb drive, USB flash drives
plug into a USB port on a computer or mobile
device. USB flash drives are convenient for mobile
users because they are small and lightweight
enough to be transported on a keychain or in a
pocket.
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in whole or in part.
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Pages 382 - 383
Figure 8-13

16. Cloud Storage
• Cloud storage is an Internet service that provides storage
to computer or mobile device users. Cloud storage is
available for home and business users, with various levels
of storage services available. Cloud storage fee
arrangements vary, depending on the user’s storage
requirements.
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Pages 383 - 384

17. Optical Discs
• An optical disc consists of a flat, round, portable
disc made of metal, plastic, and lacquer that is
written and read by a laser. Optical discs used in
computers typically are 4.75 inches in diameter
and less than 1/20 of an inch thick.
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Figure 8-14

18. Characteristics of Optical Discs
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Figure 8-15
A land causes light to reflect, which is read as binary digit 1. Pits absorb the light; this
absence of light is read as binary digit 0.

19. Optical Discs
• Optical discs commonly
store items in a single
track that spirals from
the center of the disc to
the edge of the disc
• Track is divided into
evenly sized sectors
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Figure 8-16

20. Other Types of Storage
• A magnetic stripe card is a credit card, entertainment
card, bank card, or other similar card with a stripe that
contains information identifying you and the card
• A smart card, which is an alternative to a magnetic stripe
card, stores data on an integrated circuit embedded in
the card.
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Figures 8-22 – 8-23