Components of a computer system Flashcards
(27 cards)
Define hardware
-physical components of a computer system
-devices that make up the computer
Define software
-programs for controlling the operation of a computer
-programs for processing of data
Types of input devices
-manual input devices (users enter information manually)
-direct data entry (information is automatically inputted by a reader)
How does OCR work
Scans the document, recognize characters by identifying white and black pixels
Advantages of OCR
can be used to read any printed /handwritten text
Disadvantages of OCR
-inaccurate when reading handwritten text
-might take time to read/ recognize text
Uses of OCR
optical character reader
-convert scanned image into a text file which can be edited (processed) by another software package
How does OMR work
Optical Mark Reader
-dedicated scanner device shines a beam of light onto the form
-light is reflected back to sensors
-marks reflect less light so sensors used to identify position of marks
Advantages of OMR
-saves time
-accurate (avoid human error)
Disadvantages of OMR
-can only be used in case of choices (no text)
-if mark is not dark enough/ does not fill the box, it might not be detected
-if a mark is not erased properly, it might accidentally be detected
-must have preset forms (expensive)
Data stored in magnetic stripe in bank card
-unique account number
-Bank ID
-expiry data of card
Data stored in the chip of a card
-unique account number
-PIN Code
-Bank ID
-expiry data of card
advantages of paying using magnetic stripe
-no shoulder surfing
-faster payment process
disadvantages of paying using magnetic stripe
-damaged easily (not robust), damaged easily by scratches/ magnetic field
advantages of paying using chip readers/PIN pads
-more secure due to PIN not easily scratched/damaged (more robust)
-not affected by magnetic field
disadvantages of paying using chip readers/PIN pads
shoulder surfing
Parts of RFID tag
-microchip that stores information
-antenna that is used to receive and transmit data
How is RFID activate? using bi directional data transfer
-The RFID sends radio waves/ signal to the RFID antenna in the tag
-The radio waves received by the tag’s antenna activates the microchip
- tag sends radio wave/ signal back to the reader
How does RFID read information
-the reader provides energy that activates the chip
-the antenna will send the information in the chip to the reader
Advantages of RFID
-no line of sight or contact is necessary, tag can be read from a distance
-data stored on chip, reduces need to retrieve information from a database
-it is very robust and reliable
-very fast read rate
Disadvantages of RFID
-It uses radio waves so it is easy to jam or interrupt
-it is easy to hack data transmitted by a tag
-more expensive than a barcode or chip reader system
Define RFID
radio frequency identification reader
Uses of RFID
-attendance tracking instead of check in queue
-tracking stock, passports and automobiles
-automatic passport control gates at the airport
-contactless payments
Define NFC
near field communication
