2. A World of Computers
What is computer literacy (digital literacy)?
Current knowledge and understanding
of computers and their uses
Computers are everywhere
3. What Is a Computer?
An electronic device, operating under the control of
instructions stored in its own memory,
4. What Does a Computer Do?
Four basic operations
compromise the
information processing
cycle
1. Accept data (input)
2. Process the data according to
specified rules (process)
3. Produce results (output)
4. Store the results for future
use (storage)
5. Communication
5. Data Vs Information
Data:
Collection of
unprocessed items
Processes data into
Information:
Conveys meaning and is
useful to people
6. What are the Components of a
Computer?
The six primary
components of a computer Processor
are: Control
Control Arithmetic
Arithmetic
Unit
Unit Logic Unit (ALU)
Logic Unit (ALU)
1) input devices
Instructions
2) the processor (control unit Data
and arithmetic/logic unit), Information
3) memory, Input Output
Devices
Data Memory Information
Devices
4) output devices,
5) storage devices Instructions
Data
6) communications devices Information
The processor, memory, and storage
devices are housed in a box-like case Storage
called the system unit - CPU Devices
7. INPUT: What Is Input and Input
Device?
What is input?
Data or instructions entered into memory of
computer
Data = Unprocessed text, numbers, images, audio, and video
Instructions = Programs, Commands, User responses
Input device is any hardware component that
allows users to enter data and instructions
8. INPUT: Types of input device? (1)
Keyboards Audio videos device
Pointing device Voice recognition
Mouse MIDI (musical instrument digital interface)
– Trackball Digital camera
– Touchpad
Digital video (DV) camera
– Pointing stick
Web cam
Light pen
Touch screen
Digital pen
Game controllers
9. INPUT: Types of input device? (2)
Data collection
Scanners
device
Reading Devices
(POS) terminal
Bar code reader
Automated teller
Optical reader machine (ATM)
Optical character recognition
(OCR) reads characters in OCR Biometric Input
font
Optical mark recognition (OMR) Fingerprint reader
reads hand-drawn pencil marks,
such as small circles Voice verification
Magnetic stripe card system
reader Signature
Magnetic-ink verification system
character recognition Iris recognition
(MICR) reader system
10. The System Unit
What is the system unit?
Case that contains
electronic components
of the computer used
to process data
Sometimes called
the chassis
11. The System Unit
What are common components inside the system unit?
Processor
Memory
Adapter cards
Sound card
Video card
Drive bays
Power supply
p. 185 Fig. 4-2
12. Processor
What is the central processing unit (CPU)?
Interprets and carries
out basic instructions
that operate a computer
Control unit directs and
coordinates operations in
computer
Arithmetic logic unit
(ALU) performs
arithmetic, comparison,
and logical operations
Also called the processor
13. Memory
What is memory? How is memory measured?
Electronic components that store By number of bytes available for
instructions, data, and results storage
Consists of one or
more chips on Term Abbreviation Approximate Size
motherboard or
Kilobyte KB or K 1 thousand bytes
other circuit board
Megabyte MB 1 million bytes
Each byte stored Gigabyte GB 1 billion bytes
in unique location Terabyte TB 1 trillion bytes
called an address
14. OUTPUT: What is Output?
What is output?
Data that has been processed into a useful form
Output device is any hardware component that can convey
information to one or more people
15. OUTPUT: Display Devices
Output device that visually Printer
conveys text, graphics, and Impact printer –dot matrix
video information printer
Information on display device Nonimpact printers
sometimes called soft copy
print head
Ink-jet printer
Monitor houses display device photo printer
that is packaged as separate
laser printer
peripheral
LCD (liquid crystal display) thermal printer
monitor Plotter
Plasma monitor
print cartridge
CRT (cathode-ray tube) monitor firing
chamber
ink dot
bubble resistor ink
nozzle
16. OUTPUT: Audio output device
Computer component that produces music, speech, or
other sounds
Speakers and headsets are common devices
17. OUTPUT: Other Output Devices
facsimile (fax) machine
multifunction peripheral
data projector
interactive whiteboard
18. Storage
What is storage?
Holds data, instructions, and information for future use
Storage medium is physical material used for storage
Also called secondary storage
19. Storage
What is capacity?
Number of bytes (characters) a storage medium can hold
Kilobyte (KB) 1 thousand
Megabyte (MB) 1 million
Gigabyte (GB) 1 billion
Terabyte (TB) 1 trillion
Petabyte (PB) 1 quadrillion
Exabyte (EB) 1 quintillion
Zettabyte (ZB) 1 sextillion
Yottabyte (YB) 1 septillion
20. Storage
How does volatility compare?
Storage medium is nonvolatile—contents retained when
power is off
Memory is volatile—holds data and instructions temporarily
ON OFF
Screen Display Display Display
Volatile
appears disappears
Memory Data and Data and
(most RAM) instructions instructions
(chips on motherboard) available to erased
Nonvolatile
user
Storage Medium Contents Contents
(hard disks, CDs, DVDs, available to retained
USB flash drives, etc.) user
21. Storage device:
Hard- Disc
High-capacity storage, most are housed
inside the system unit
Consists of several inflexible, circular
platters that magnetically store data,
instructions and information electronically
External hard disk—freestanding
hard disk that connects to system unit
Removable hard disk—hard disk
that you insert and remove
from hard disk drive track
sector
Magnetic disc
use magnetic particles to store items on a
disk’s surface.
read/wri
Magnetic Tape head
is a magnetically coated ribbon of plastic
housed in a tape cartridge platter
sides
cylinder
22. Other Storage device:
Floppy disc
Is an inexpensive portable storage
medium
Optical Disc
is a portable storage medium that consists of a
flat, round, portable disc made of metal,
plastic, and lacquer that is written and read by
a laser
CD-ROM (Compact disc read-only
memory)
CD-RWs (Compact disc-rewritable)
erasable disc you can write on
multiple times
CD-R (compact disc-recordable)
disc you can write on once
DVD-ROM (digital versatile disc-ROM or
digital video disc-ROM)
Online storage
microfilm and microfiche
23. Miniature Mobile Storage Media
What is miniature mobile storage media?
Storage for small mobile devices
•flash memory cards
•USB Flash Drive
•smart card
24. Computer Software
What is software?
Consists of a series
of instructions that
Also called a
tells the computer
program
what to do and
how to do it
Two types of software: system software and
application software
25. Computer Software
What is system software?
Programs that control or maintain the operations of
the computer and its devices
Operating System (OS)
is a set of programs
that coordinates all
activities among
computer hardware Utility Programs allow the user to
devices perform maintenance-type tasks
usually related to managing a
computer, its devices or its programs
27. Operating Systems
Operating system
Microsoft Windows Vista
Microsoft Windows XP
Apple Mac OS X
Linux
Booting
Process of starting or restarting a computer
Spooling
Sending print jobs to buffer instead of directly to printer
Graphical user interface (GUI)
– User interacts with menus and visual images such as buttons and other
graphical objects
Program management features of operating systems
Multitasking, multiprocessing, multiuser and fault-tolerant
28. Operating System Utility Programs
What is a utility program?
System software that performs
maintenance-type tasks
Also called
utility
29. Application Software
What is application software?
Programs designed to make users more productive
and/or assist them with personal tasks
30. Application Software
How is software distributed?
Packaged software, mass-produced
Custom software, performs functions specific to a
business or industry
Web-based software, hosted by a Web site
Open source software, provided for use, modification,
and redistribution
Shareware, copyrighted software that is distributed
free for trial period
Freeware, copyrighted software provided at no cost
Public-domain software, freeware with no copyright
restrictions
31. Communications Devices
is a hardware component that enables a computer to
send and receive data, instructions, and information to
and from one or more computers
Transmission media
Network through wire or wireless
– Telephone lines, cables, cellular radio networks & satellites
Used to share
Resources
Hardware
devices Software
programs Saves
Data time
Information and
money
32. Networks and the Internet
A network is a collection of computers and devices
connected together, often wirelessly, via
communications devices and transmission media
Local area network (LAN)
Wide area network(WAN)
33. Networks and the Internet
The world’s largest network is the Internet, which is a
worldwide collection of networks that connects millions of
businesses, government agencies, educational institutions, and
individuals
Internet service provider (ISP)
Online service provider (OSP)
Wireless Internet service provider (WISP)
34. Networks and the Internet
• The World Wide Web contains billions of
documents called Web pages
Web page
Web site
Web browser
Uniform Resource Locator (URL)
Hypertext transfer protocol
35. Networks and the Internet
Why do users access the Internet?
1. Communications
2. Research and Information
3. Shopping
4. Banking and Investing
5. Classes
6. Entertainment
7. Download Music
8. Share Information
36. Networks and the Internet
• When you conduct business activities online, you
are participating in electronic commerce, also
known as e-commerce
– Business to consumer (B2C)
– Consumer to consumer (C2C)
– Business to business (B2B)
37. Advantages and Disadvantages
of Using Computers
What are the advantages of using computers?
Speed Reliability Consistency
Storage Communications
Next
38. Advantages and Disadvantages
of Using Computers
What are the disadvantages of using computers?
Violation of
Public Safety
Privacy
Impact on Impact on
Health Risks
Labor Force Environment
39. Categories of Computers
What are the categories of computers?
Personal Computers
(desktop)
Mobile Computers and
Mobile Devices
Game Consoles
Servers
Mainframes
Supercomputers
Embedded Computers
40. Servers
What types of servers are there?
A server controls access to network
resources and provides centralized
storage
Mainframe Very powerful,
expensive computer that supports
thousands of connected users
Supercomputer The fastest, most
powerful, most expensive
computer. Used for applications
requiring complex mathematical
calculations
41. Elements of an Information System
What are information system elements?
Hardware
Software
Data
People
Procedures
42. Examples of Computer Usage
What software is available for a home user?
Personal finance
management
Web access
Communications
Entertainment
43. Examples of Computer Usage
What software is available for a small
office/home office (SOHO) user?
Productivity
software
Specialty
software
Web usage
E-mail
44. Examples of Computer Usage
What is available for
a mobile user?
Hardware
Notebook computers
Tablet PCs
Internet-enabled PDAs
Smart phones
Software
Word processing
Spreadsheet
Presentation graphics
software
45. Examples of Computer Usage
What are the needs of a power user?
Speed and large amounts of storage
Types of power users
Engineers
Scientists
Architects
Desktop publishers
Graphic artists
46. Examples of Computer Usage
What are the needs of the large business user?
Payroll
Inventory
E-commerce
Desktop
publishing
47. Computer Applications in Society
What are some examples
of computer applications
in society?
Education
Finance
Government
Health Care
Science
Publishing
Travel
Manufacturing