1.1.3

• Input devices


  • Keyboard
  • Webcam
  • Magnetic stripe reader
  • Barcode reader
• Output devices


  • Speakers
  • Printers
  • Projector
• Input/output devices


  Devices that can be used for both input and output, like a touch screen
• Considerations when purchasing input devices

  • Speed of input
  • Accuracy of input
  • Cost
  • Relevance to task
• Optical storage


  Devices that use lasers to read and write binary information represented by reflective and scattering portions on the disc surface
• Optical storage devices


  • CDs
  • DVDs
  • Blu-Ray
• CDs


  • Small, thin and light
  • Used for audio, text and digital images
  • Easily damaged
  • Limited storage capacity
  • Relatively slow transfer speeds
• DVDs


  • Higher storage capacity than CDs
• Blu-Ray


  • More than five times the storage of DVDs
• Magnetic storage


  Devices that represent binary information using two magnetic states: polarised and unpolarised
• Hard disk drives


  • High capacities
  • Somewhat slow data transfer speeds
  • Prone to damage from movement
• Magnetic tape


  • Bulky
  • Superseded by more modern technology
• Floppy disks


  • Portable
  • Typical storage capacity of 1MB, up to 200MB
• Flash storage


  Uses semiconductor logic gates to store electrical charge representing binary information
• Flash storage


  • Fast and compact
  • Electronically erasable and reprogrammable
  • Non-volatile
  • More expensive per gigabyte than other storage
• Solid state drives (SSDs)

  Flash memory storage devices with no moving parts, making them more resistant to damage
• Solid state drives (SSDs)

  • Light and portable
  • High data transfer rates
  • More expensive than hard disk drives
  • Limited lifespan due to wear on memory cells
• RAM


  Random access memory, a type of fast main memory used to store data and programs the computer is currently using
• RAM


  • Volatile, loses information when power is lost
  • More expensive per gigabyte than secondary storage
• ROM


  Read only memory, cannot be modified once programmed
• ROM


  • Non-volatile, retains data when powered off
  • Useful for storing fixed sequences of instructions like startup routines
• Virtual storage


  Storing information remotely so it can be accessed from any connected device
• Virtual storage


  • Abstraction of multiple physical drives
  • Convenient to access and share
  • Limited by network speed
  • High costs