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Introduction to Computers

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Title: Introduction to Computers


1
Introduction to Computers
  • And How to Purchase, Install, and Maintain a
    Personal Computer

2
Objectives
  • Define the term computer and discuss the four
    basic computer operations input, processing,
    output, and storage
  • Define data and information
  • Explain the principal components of the computer
    and their use
  • Describe the use of floppy disks, hard disks, and
    other storage media
  • Discuss computer software and explain the
    difference between system software and
    application software

3
Objectives cont
  • Identify several types of personal computer
    application software
  • Discuss computer communications channels and
    equipment and the Internet and World Wide Web
  • Explain how to purchase, install, and maintain a
    personal computer
  • Define e-commerce

4
What is a computer?
  • Computer
  • an electronic device, operating under the control
    of instructions stored in its own memory unit
  • this memory unit can
  • accept data input
  • manipulate data process
  • produce information output
  • store results for future use - storage

5
What does a computer do?
  • Computers perform four general operations
  • input, process, output, and storage
  • Information processing cycle
  • inputting, processing, outputting, and storing
    make-up this cycle
  • Processing requires data
  • data collection of raw facts, figures, and
    symbols given to a computer during the input
    operation
  • Manipulate data to create information
  • information data that is organized, meaningful,
    and useful

6
Why is a computer so powerful?
  • Power is derived from the computers capability
    to perform the information processing cycle with
    speed, reliability, and accuracy
  • The computers capacity to store huge amounts of
    data and information
  • The computers ability to communicate with other
    computers

7
How does a computer know what to do?
  • It must be given a detailed set of instructions
  • These instructions are called a computer program
    or software
  • Executes one program instruction after another
    until the job is complete

8
What are the components of a computer?
  • Six primary components
  • input devices
  • the processor
  • memory
  • output devices
  • storage devices
  • communications devices
  • the processor, memory, and storage device are
    housed in a box-like case called the system unit

9
Input Devices
  • Input device any hardware component the allows
    you to enter data, programs, commands, and user
    responses into a computer
  • primary input devices
  • keyboard
  • mouse
  • other input devices
  • digital camera
  • scanner
  • microphone

10
Input Devices cont
  • The Keyboard
  • desktop computer keyboard typically has 101 to
    105 keys
  • handheld computers use an onscreen keyboard and
    use a stylus to select keys
  • The Mouse
  • a pointing device that fits under the palm of
    your hand
  • control the movement of the pointer on the screen
    and make selections from the screen
  • one to five buttons
  • bottom is flat and contains a mechanism or ball
    that detects movement
  • notebooks have a pointing device built into the
    keyboard

11
Processor
  • Processor or central processing unit (CPU)
    interprets and carries out the basic instructions
    that operate a computer
  • made up of the control unit and arithmetic/logic
    unit
  • control unit interprets the instructions
  • arithmetic/logic unit performs the logical and
    arithmetic processes
  • 42 million transistors and performs operations 10
    million times in a tenth of a second

12
Memory
  • Memory or random access memory (RAM) electronic
    components that store instructions waiting to be
    executed by the processor, data needed by those
    instructions, and the results of processed data
  • consists of one or more chips on the motherboard
  • motherboard or system board main circuit board
    to which electronic components are attached
  • memory is measured in kilobytes or megabytes
  • 1 kilobyte (K or KB) 1,000 memory locations
  • 1 megabyte (M or MB) 1,000,000 memory locations
  • memory location or byte stores one character

13
Output Devices
  • Output devices make information from processing
    available for use
  • can be presented in many forms
  • printed report or displayed on a screen
  • printers and display devices are common output
    devices for word processing, spreadsheets, and
    database management

14
Output Devices cont
  • Printers
  • two kinds of printers
  • impact printers strikes an inked ribbon against
    the paper (dot matrix printer)
  • Nonimpact printers form characters by means
    other than striking a ribbon against paper
    (ink-jet printers or laser printers)
  • advantage print higher-quality text and
    graphics, better job printing different fonts,
    quieter, can print in color

15
Output Devices cont
  • Display devices an output device that visually
    conveys text, graphics, and video information
  • monitor plastic or metal case that houses a
    display device
  • two types of monitors CRT and LCD
  • cathode ray tube (CRT) television- like, most
    common
  • LCD or flat panel monitor uses a liquid display
    crystal, similar to a digital watch
  • surface of screen is composed of individual
    picture elements called pixels
  • resolution of 800 x 600 480,000 pixels
  • each pixel can be illuminated to form parts of a
    character or grpahic shape on the screen

16
Storage Devices
  • Storage devices used to store instructions,
    data, and information not being used in memory
  • six types of storage devices
  • floppy disks
  • zip disks
  • optical discs
  • tape
  • miniature storage media

17
Storage Devices cont
  • Floppy disks or diskette
  • portable, inexpensive storage medium that
    consists of a thin, circular, flexible plastic
    disk with a magnetic coating enclosed in a
    square-shaped plastic shell
  • typically can store up to 1.44 megabytes of data
    or 1,474,560 characters
  • a portable storage medium
  • portable means you can remove the medium from one
    computer and carry it to another computer
  • floppy disk drive device that can read from and
    write to a floppy disk

18
Storage Devices cont
  • Floppy disks cont
  • a type of magnetic disk, which uses magnetic
    patterns to store items on its surface
  • read/write storage media
  • can access (read) data from and place (write)
    data on a magnetic disk
  • must be formatted
  • formatting process of preparing a disk for
    reading and writing by organizing the disk into
    storage locations called tracks and sectors
  • track a narrow recording band that forms a full
    circle on the surface of the disk
  • sector capable of holding 512 bytes of data
  • 80 track per side and 18 sectors per track
  • access time time required to access and
    retrieve data

19
Storage Devices cont
  • Zip Disk portable magnetic media
  • can store up to 750 MB
  • can be built-in or external
  • make it easier to transport many files or large
    items
  • graphics, audio, or video files
  • back up important data and information
  • backup a duplicate of a file, program, or disk
    that you can use in case the original is lost,
    damaged, or destroyed

20
Storage Devices cont
  • Hard disks consists of one or more rigid metal
    platters coated with a metal oxide material that
    allows data to be recorded magnetically
  • data is recorded on a series of tracks
  • spin 5,400 to 7,200 revolutions/minute
  • number of platters vary
  • storage capacity one billion characters to more
    than 200 billion characters
  • 1 billion bytes 1 gigabyte (GB)

21
Storage Devices cont
  • Optical discs storage medium that consists of a
    flat, round, portable, metal storage medium
  • 4.75 inches in diameter
  • less than 1/20 of an inch thick
  • Two types of optical discs
  • CD
  • DVD
  • Variety of formats
  • CD-ROM, CD-R, CD-RW, DVD-ROM, DVDRW

22
Storage Devices cont
  • CD-ROMs or compact disc read-only memory- type of
    optical disc that uses laser technology for
    recording
  • can contain audio, text, graphics, and video
  • can only read, cannot erase or modify the content
  • holds 650 MB 1 GB of data
  • CD-R or compact disc-recordable multisession
    optical disc that you can record your own items
    on
  • can read from many times
  • can write on each part only one time
  • cannot erase

23
Storage Devices cont
  • CD-RW or compact disc-rewritable an erasable
    disc you can write on multiple times
  • write and rewrite data, instructions, and
    information multiple times
  • DVDs technology that can be used to store large
    amounts of text and even cinema-like videos
  • DVD-ROM or digital video disc-ROM high capacity
    optical disc
  • store 4.7 GB to 17 GB
  • read-only

24
Storage Devices cont
  • DVDRW or DVD-rewriteable can erase and record
    multiple times
  • major use
  • edit videos from a video camera or VCR, stored
    and edited on your computer, and then written to
    a DVDRW disc
  • Tape magnetically coated ribbon of plastic
    housed in a tape cartridge capable of storing
    large amounts of data and information at a low
    cost
  • primarily used for long-term storage and backup

25
Storage Devices cont
  • Miniature Storage Media rewritable media in the
    form of a flash memory card
  • solid-state device that consists entirely of
    electronics and contain no moving parts
  • used with PDAs, digital cameras, music players,
    and smart phones
  • used to store digital images, music, and documents

26
Communications Devices
  • Communications device hardware component that
    enables a computer to send (transmit) and receive
    data, instructions, and information to and from
    one or more computers
  • widely used communication device is the modem
  • communications occur over transmission media
  • cables, telephone lines, cellular radio networks,
    and satellites
  • some are wireless

27
Computer Software
  • two types of software
  • system software
  • application software
  • System software programs to control the
    operations of computer equipment
  • operating system set of programs that tell the
    computer how to perform the functions of loading,
    storing, and executing an application program and
    how to transfer data
  • booting when a computer is turned on, the
    operating system is loaded into the computers
    memory from auxiliary storage
  • graphical user interface (GUI) visual cues or
    icon symbols

28
Computer Software cont
  • Application Software programs that tell a
    computer how to produce information
  • examples personal information manager,
    accounting, computer-aided design, desktop
    publishing, picture and video editing, and
    educational
  • commonly used applications word processing,
    electronic spreadsheet, and presentation graphics
  • software package Microsoft Office

29
Computer Software cont
  • Word processing software used to create, edit,
    format, and print documents
  • advantage users can easily make changes to the
    document
  • Electronic spreadsheet software user can add,
    subtract, and perform user-defined calculations
    on rows and columns of numbers
  • eliminates tedious recalculations, easily
    converted into a graphic form

30
Computer Software cont
  • Database software user can enter, retrieve, and
    update data in an organized and efficient manner
  • Can access data in different ways and create
    custom reports
  • Presentation graphics software allows users to
    create documents called slides to be used in
    presentations

31
Networks and the Internet
  • Network collection of computers and devices
    connected via communications media and devices
    such as cables, telephone lines, modems
  • users can share resources, such as hardware
    devices, software programs, data, and information
  • saves time and money
  • LAN or local area network network that connects
    computers in a limited geographic area
  • computer lab, offices, groups of buildings
  • WAN or wide area network network that covers a
    large geographical area
  • districts offices of a national corporation

32
Networks and the Internet cont
  • The Internet worldwide collection of networks
    that links together millions of computers by
    means of modems, telephone lines, cables, and
    other communications devices and media
  • world largest network
  • use the Internet for a variety of reasons
  • Sending messages (e-mail), accessing information,
    shopping, meeting and conversing with people, and
    accessing sources of entertainment and leisure

33
Networks and the Internet cont
  • Connect to the Internet in one of two ways
  • through an Internet service provider
  • through an online service provider
  • Internet service provider (ISP) organization
    that supplies connections to the Internet for a
    monthly fee
  • Online service provider (OSP) provides access
    to the Internet, but it also provides a variety
    of other specialized content and services

34
Networks and the Internet cont
  • The World Wide Web or the Web contains billions
    of documents called Web pages
  • most popular segment of the Internet
  • Web page document that contains text, graphics,
    sound, and/or video and has built-in connections,
    or hyper-links, to other Web documents
  • Web site related collection of Web pages
  • Web browser software program used to access and
    view Web pages

35
Networks and the Internet cont
  • Uniform Resource Locator or URL unique Web page
    address
  • consists of a protocol, domain name, and
    sometimes the path to a specific Web page or
    location in a Web page
  • URLs begin with http//
  • http stands for hypertext transfer protocol
  • domain name identifies the Web site, which is
    stored on a Web server
  • Web server computer that delivers (serves)
    requested Web pages

36
Networks and the Internet cont
  • Electronic Commerce or e-commerce conducting
    business activities online
  • Three types of e-commerce
  • Business to consumer (B2C) sale of goods to the
    general public
  • Consumer to consumer (C2C) one consumer selling
    directly to another
  • Business to business (B2B) goods and services
    to other businesses
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