TLE 9

• Computer


  An electronic device, operating under the control of instructions stored in its own memory that can accept data (input), process the data according to specified rules, produce information (output), and store the information for future use
• Types of computers

  • Analog computers
  • Digital computers
  • Hybrid computers
• Analog computers


  • Use continuously form of physical quantities and can perform calculations with the help of measures
  • Used in hospitals, aircrafts and so on
• Digital computers


  • The most common computers that perform calculations and logical operations
• Hybrid computers


  • Computers with combined features of both digital and analog type
  • Operate by counting as well as by measuring
• Classification of computers

  • Mainframe computers
  • Minicomputers
  • Servers
  • Supercomputers
  • Microcomputers
• Mainframe computers


  • Multi-user, multiprogramming and high-performance
  • Operate at a very high speed
  • Have a very large storage capacity
  • Can handle the workload of many users
  • Used in centralized databases and organizations like banks or companies
• Minicomputers


  • Digital computers generally used in multi-user system
  • Have high processing speed and high storage capacity
• Servers


  • Computers designed to provide services to client machines in a computer network
  • Have larger storage capacities and powerful processors
  • Very large in size
  • Designed to be fail-safe and resistant to crash
• Supercomputers


  • The fastest and the most expensive machines
  • Can perform trillions of calculations per second
  • Used for weather forecasting, climate research and aircraft design
• Microcomputers


  • Computers with a microprocessor and its central processing unit
  • Do not occupy space as much as mainframes
• Personal computers

  • Desktops
  • Laptops
  • Netbooks
  • Personal Digital Assistants (PDAs)
  • Tablet Computers
• Desktops


  • The most common type of microcomputer
  • Stand-alone machine that can be placed on the desk
• Laptops


  • Miniaturized and optimized for mobile use
  • Run on a single battery or an external adapter that charges the computer batteries
• Netbooks


  • Fall in the category of laptops
  • Inexpensive and relatively smaller in size
  • Had a smaller feature set and lesser capacities in comparison to regular laptops
• Personal Digital Assistants (PDAs)


  • Handheld computer
  • Have a touch screen and a memory card for storage of data
  • Can be used as portable audio players, web browsers and smart phones
  • Can access the Internet by means of Bluetooth or Wi-Fi communication
• Tablet Computers


  • Mobile computers that are very handy to use
  • Use the touch screen technology
  • Come with an onscreen keyboard or use a stylus or a digital pen
• Computer


  A programmable electronic device that processes data via instructions to output information for future use
• Data and Information


  Raw facts and figures that has no meaning processed via a set of instructions, and Meaning attached to data letters, pictures, symbols or sounds
• Why users use computers


  • For their data processing speeds, accuracy, storage capacity and ability to work for long periods
• A computer system consists of both hardware and software
• Hardware is a set of instructions called programs the computer uses to carry out tasks while Software are all the parts of the computer you can see and touch and is also known as peripherals
• Computer peripheral


  Any external devices for the computer to enter any information and instructions, for storage or processing and to deliver the processed data to a human operator
• Types of peripherals

  • Input, output and storage devices
• Devices of a computer

  • System Unit
  • Motherboard / Mainboard / System Board
  • CPU (Central Processing Unit)
  • Primary storage
  • Adapters
  • Power Supply Unit (PSU)
  • Hard Disk Drive (HDD)
  • Optical Disk Drive (ODD)
  • Digital Versatile Disc (DVD)
• Input Device

  A device that accepts data and instructions from the user or from another computer system
• Output Device

  Any piece of computer hardware that displays results after the computer has processed the input data that has been entered
• Types of Input Devices

  • Keyboard
  • Mouse
  • Scanner
  • Microphone
  • Webcam
• Output Devices


  • Computer Display Monitor
  • LCD Projectors
  • Printer
  • Speakers
• Storage Device


  Any apparatus for recording computer data in a permanent or semipermanent form
• Types of Storage Devices

  • Compact disc (CD)
  • Digital Versatile Disc (DVD)
  • USB flash drive
  • Hard disk drive (HDD)
• Input device is a hardware device capable of holding information
• One of the output devices is the monitor
• The projector is an output device that gives illustrations on paper
• Adapters enable the computer to use a peripheral device for which it does not have the necessary connections or circuit boards
• Motherboard is the main circuit board of a computer
• Peripheral device


  Connected to the computer to perform a specific function into the computer
• Hardware


  The physical, touchable, electronic and mechanical parts of a computer
• Devices attached to the computer

  • Input
  • Output
  • Storage
• Input device


  Hardware device capable of holding information