Chapter 1 Flashcards
State what is meant by the term hardware.
Physical components of a computer system that can be touched.
State what is meant by the term software.
Programs controlling the operation of a computer system that cannot be touched.
What is an Optical Character Reader (OCR) used for?
An OCR converts a scanned image into a text file which can be edited and processed by another software package such as word, spreadsheets or databases.
What is an Optical Mark Reader (OMR) used for and how does it work?
To mark multiple choice candidate exam answers where responses are recorded by shedding light in specific places.
Dedicated scanner device shines light onto the form and the light is reflected back to the sensors, the marks reflect less light so sensors can identify the positions of the mark.
What is a barcode reader and how does it work?
The code is scanned with a red light, a sensor detects the reflected light, according to the intensity of the reflections, the code is detected. Used in supermarkets to identify product prices.
What is a quick response scanner (QR)?
Scan OR codes. The codes in the pattern contain small amounts of data such as website URLs or contact details.
Many smart phones have QR code readers, and the codes can be scanned quickly to access information.
The codes avoid the user having to remember long numbers and website addresses because the reader will quickly convert the QR code into information.
Describe what an RFID chip is and how data can be read from it.
An RFID chip is a tag, label or card that can exchange data using radio frequency waves.
The RFID reader send radio waves which are received by the tag’s antenna which active the microchip, the tag sends a radio wave back. The reader then activates the chip with energy and sends the information in the chip to the reader to be stored on a data. base.
Describe what a near field communications (NFC) reader is.
Used for contactless transfer of information including payments for items using a smartphone or transmissions of information between smartphones.
NFC requires the sender and receiver to be close together, unlike in RFID which makes it more secure.
NFC device can act as a receiver and reader.
What are the advantages and disadvantages of biometric readers such as: fingerprint scanners, retina scanners, iris recognition, face recognition and voice recognition)
Advantages:
- Unique as no two people have the same fingerprint.
- Difficult to be copied.
- Impossible to be lost of forgotten.
Disadvantages:
- Expensive equipment and takes time to set up.
- Needs a lot of storage space.
- Security issues regarding storing people’s biometric data.
What are the three types of printers?
Laser printer, inkjet printer and dot matrix printer
What are the properties of a laser printer?
Low noise, highspeed, separate sheets and use toner.
Describe Random Access Memory (RAM)
Read and write, volatile (loses its memory when switched off), used to store files and data currently in use.
What are the properties of an inkjet printer?
Medium noise, medium speed, high quality, highest running cost, lowest initial cost, most suitable for printing images, uses droplets.
What are the properties of a dox matrix printer?
high noise, low speed, low quality, continuous stationary, creates carbon copies, uses ribbon droplets.
Describe Read Only Memory (ROM)
Read only, non-volatile (doesn’t lose its memory when switched off), used to store instructions to start up the computer.
Describe different flash memory cards.
SD card - Compatible with most devices.
XD card - used for camaras.
CFast card - used for gaming devices.
The advantages and disadvantages of using cloud rather than a hard drive.
Advantages
- Accessed over multiple devices in any place
- Easier to add storage capacity
- Ability to synchronize files across multiple devices
- Backups are automatic
- Cannot be lost of misplaced
Disadvantages
- If internet connection is unstable of slow there will be problems accessing files
- Cloud storage can be expensive is extra storage capacity is needed
-It is easier to hack the cloud as the data is stored on servers for long periods of time
- Risk of fires or floods can cause data loss
Advantages and disadvantages of gesture-based interface.
Advantages:
- Easy to use
- No mechanical devices needed
- No physical contact required
Disadvantages:
- Limited range of commands
- Can pick up unintentional movements
- User has to be near a camera or sensor
Advantages and disadvantages of dialogue-based interface.
Advantages:
- Hand free commands
Disadvantages:
- may lead to errors due to vocal accents
- Expensive to develop
- Affected by background noise
Describe the benefits of using command line interface (CLI) rather than graphical user interface (GUI)
Benefits:
- CLI is not restricted to premeditated options
- The CLI user has more control over the computer settings
- CLI used less memory that the GUI
- CLI requires less processing power
Drawbacks:
- CLI commands have to be learnt
- CLI commands have to be types in exactly
- More risks of errors in data entry with CLI
- CLI commands have to be typed in with a keyboard rather than touch screen
- CLI is used by experts
