Computer Science Exam 2

  1. Input
    any data or instructions that are used by a computer
  2. optical mouse
    no moving parts
  3. trackball
    roller ball
    control the pointer by rotating a ball with your thumb
  4. multitouch screens
    • touch by more than one finger
    • rotate grpahical objects with your hand
    • zoom in and out by pinching and stretching your fingers
  5. scanners (4 tyoes)
    • optical
    • card readers
    • bar code readers
    • character and mark recognition
  6. optical scanners
    accepts documents consisting of text and/or images and convert them to machine-readable forms
  7. card reader
    interprets encoded info stored on cards, credit card, debit cards, access cards
  8. RFID
    (radio frequency card readers)
    microchip contains the user's encoded info
  9. magnetic ink character recognition
    banks used to automatically read the unusual numbers on the bottom of checks and deposit slips
  10. optical-mark recognition
    • sense pencil marks
    • score standarized tests
  11. voice recognition systems
    • use microphone sound card
    • allows users to opeerate computers with voice
  12. clarity
    most important characteristic of a monitor
  13. resolution
    the higher the resolution (the more dots, pixels) the clearer the image
  14. Dot (pixel) pitch
    • the distance between each pixel
    • lower the pitch the clearer the image
  15. active matrix
    thin film transistor (TFT)
    • each pixel is independently activiated
    • better clarity
    • more $
    • more power
  16. cathode-ray tubes (CRT)
    • similar in size and technology to tv's
    • low cost and excellent resolution
    • bulky and less enegery efficient
  17. printer resolution
    dpi (dots per inch)
  18. printer speed
    measured by # of pages per minute
  19. printer memory
    store printing instructions and documents waiting to be printing
  20. ink-jet printer
    most widely used
  21. personal laser printer
    • less $
    • used by single users
    • print 15-17 pages per minute
  22. shared laser printers
    • used by group
    • 50 pages per minute
  23. thermal printer
    uses heat sensitive paper
  24. audio output devices
    • speakers
    • headsets
  25. voice over IP (VOIP)
    transmission of telephone calls over computer networks
  26. secondary storage
    • permanent
    • data and programs can be retained after the computer has been shut off
  27. media
    physical material that holds the data and program
  28. capacity
    measures how much a particular storage medium can hold
  29. storage devices
    hardware that reads from and writes to stroage media
  30. density
    how tightly charges can be packed next to one another on a disk
  31. tracks
    rings of concentric circles without visible grooves
  32. sectors
    • wedge-shaped sections
    • cylinders
  33. internal hard disk
    • inside system unit, c drive
    • store operating systems and important applications such as Word and Excel
  34. external hard drives
    • use same technology as internal hard disks and are used primarily to complement an internal hard disK
    • can be easily removed
  35. disk caching
    improves processing by acting as a temporary high speed holding area between a secondary stroage device and the CPU
  36. RAID
    (redundant arrays of inezpensive disks)
    • ezpanded storage capability
    • fast access
    • high reliability
  37. Optical Disks
    • can hold over 100 gigabytes of data
    • laser beam is used to alter the surface of a plastic or metallic disc to represent data
    • optical disks use reflected light to represent 0's and 1's
    • the 0's and 1's are represented by lands-flat areas, pits, bumpy areas
    • a single track spirals to the center of the disc, the divided into sectors
  38. CDs
    • read only
    • used to distribute large software aplication packages
  39. CD-RW
    • rewritable
    • erasable optical disks
  40. CD-R
    • recordable
    • write once
  41. Blu-Ray Disc
    • standard for hi def optical disc
    • blue colored laser reads
    • 25 to 100 gigabytes
  42. solid state storage devices
    no moving parts
  43. solid state drives (SSDs)
    like an internal hard disk but contains solid state memory instead of magnetic hard disks
  44. flash memory cards
    credit card sized solid state stroage devices used in mobile phones and GPS
  45. USB drives
  46. Cloud storage
    • online storage
    • Google Apps., Amazon S3
    • web server runs applications, computer displays result
    • software does not have to be upgraded for each computer in network
  47. enterprise storage system
    promote safe and efficient use of data across the networkd within their organiztions
  48. storage area network
    provides network to house data in remote locations
  49. wireless revolution
    single most dramatic change in connectivity and communications in the past 5 years has been the widespread use of mobile or wireless telephone to connect to the internet and share info
  50. fiber optic cable
    • tiny tubes of glass
    • transmit data at lightning speed
  51. microwave
    high frequency radio waves
  52. modems
    convert digital signals to analog signals or vice versa
  53. modulation
    converting form digital to analog
  54. demodulation
    converting from analog to digital
  55. transfer rate
    • the speed modems transmit datae
    • measure in thousands of bits (kilobits) per sec
  56. DSL
    digital subscriber line
    using existing phone lines to provide high speed connections
  57. leased lines
    large corporations leasing special high speed lines from telephone companies
  58. optical carrier
    lines with higher speed have replaced leased lines
  59. DSL (digital subscriber line)
    AdSL (asymmetric digital subscriber line)
    use telephone lines to provide high speed service
  60. cable modems
    • use television cable
    • faster than DSL
  61. bandwidth
    measurement of the width or capacity of the communication channel
  62. voiceband
    low bandwidth
    standard telephone communications
  63. medium hand
    special leased lines to connect minicomputers and mainframes
  64. broadband
    high capacity transmissions
  65. baseband
    connect individual computers that are close together
  66. protocol
    rules for exchanging data between computers
  67. TCP/IP
    transmission control protocol/ internet protocol)
    • standard protocol for the internet
    • essential features of this protocol involve:
    • 1. identifying sending and receiving devices and 2. breaking info into small parts for transmission across the internet
  68. IP address
    Internet protocol address
  69. Identification
    • a computer's unique address
    • internet uses it to deliver email and to locate Web sites
  70. Domain Name Server (DNS)
    converts text based addresses to IP addresses
  71. switch
    central node that coordinates the flow of data by sending messages directly between sender and receiver nodes
  72. WLAN
    (wireless local area network)
    uses radio frequencies to go through wireless access points to communicate
  73. most popular PAN technology
  74. Newtwork architecture
    describes how a network is arranged and how resources are coordinated and shard
  75. network topology
    the way networks are arranged and configured
  76. Tree network
    (hierarchial network)
    • each device is connected to a central node
    • the node is in turn connected to other nodes and so forth
  77. mesh network
    • each node has more than one connection to the other nodes
    • self healing property
  78. terminal server network
    central processing
  79. peer to peer network
    nodes have equal authority
  80. Intranet
    private network that resembles the internet
  81. Extranet
    private network that connects mroe than one organization
  82. Intrusion detection systems (IDS)
    • use statistical techniques to analyze traffic
    • recognize signs of network attack and access
  83. info resellers
    • can trade info without the consent of the individual
    • create electronic profiles with personalized descriptions of the individual
  84. private network
    • 75% of businesses search employees emails using snoopware
    • this is legal
  85. snoopware
    • record almost everything you do on your computer
    • employers have to alert employees that they are being monitored
  86. cookies
    deposited to your hard drive from the web sites you've visited
  87. traditional cookies
    • monitor your acitivity at a single site
    • provide customized service
  88. ad network cookies
    (adware cookies)
    monitors acitivities across different sites
  89. spyware
    programs that are designed to secretly record and report individual's acrivities on the internet
  90. computer monitoring software
    keystroke loggers, study every key stroke of the user
  91. hackers
    • create or omprove programs and share them with fellow hackers
    • not criminals
  92. crackers
    • create and share programs designed to gain unauthorized access to computer systems
    • criminals
  93. Computer Fradu and Abuse Amendments Act
    federal defense to punish criminals creating and spreading viruses
  94. worms
    • fill computer systems with self replicationf info and thous slow down or stop the computer
    • come through emails and downloads
  95. zombies
    computers infected by a virus, worm, or trojan horse that allows them to be remotely controlled for malicious purposes
  96. Botnet
    collection fo zombie computers
  97. denial of service attack (DoS)
    attempts to clow down or stop a computer system by flooding a computer with requests for info and data
  98. dictionary attack
    uses software to try thousands of common words equentially in an attempt to gain unathorized access
  99. encrypting data
    the process fo coding info to make it unreadable except to thouse who have a special piece of info known as an encryption key
  100. digital millennium copyright act
    right of a program owner to make backup copy of any program and none of these backup copies can be legally resold or given away
Card Set
Computer Science Exam 2