TLEE 2

• Input Devices


  Devices that allow a user to enter data and instructions into a computer.
• Keyboard

  • One of the primary input devices used with a computer that looks similar to those found on electric typewriters, but with some additional keys. Keyboards allow you to input letters, numbers, and other symbols into a computer that can serve as commands or be used to type text.
• Mouse


  • It is a pointing device. The mouse is rolled over the mouse pad, which in turn controls the movement of the cursor in the screen. You can click, double-click or drag the mouse. Its sensor notifies the speed of its movements to the computer, which in turn moves the cursor/pointer on the screen.
• Scanner


  • Is a device that takes a picture of an image that exists outside the computer, such as a photograph or a drawing on paper. As the scanner takes the picture, it digitizes the image (breaks it up into dots that can be recreated on the computer screen with electronic signals), and send this digital information to the computer as a file.
• Track ball


  • Is a computer cursor control device used in many notebook and laptop computers. The trackball is usually located in front of the keyboard toward the user. Essentially, the trackball is an upside-down mouse that rotates in place within a socket.
• Light pen


  • A light-sensitive computer input device, basically a stylus, that is used to select text, draw pictures and interact with user interface elements on a computer screen or monitor. It allows the user to point, to displayed objects or drawn on screen.
• Optical Character Reader


  • Is a device which detects alphanumeric characters printed or written on a paper. Optical character recognition refers to both the technology and process of reading and converting typed, printed or handwritten characters into machine-encoded text or something that the computer can manipulate.
• Bar Code Reader


  • Also called a price scanner or point-of-sale (POS) scanner, is a hand-held or stationary input device used to capture and read the information contained in a barcode. A barcode reader consists of a scanner, a decoder (either built-in or external), and a cable used to connect the reader with a computer.
• Voice Input Systems


  • It converts spoken words to machine language form. A microphone is used to convert human speech into electric signals. The signal pattern is then transmitted to a computer when it is compared to a dictionary of patterns that have been previously placed in a storage unit of a computer. When a close match is found, the word is recognized.
• Digital Camera


  • Records and stores photographic images in digital form. Many current models are also able to capture sound or video, in addition to still images. These stored images can be uploaded to a computer immediately or stored in the camera to be uploaded into a computer or printer later.
• Output Unit


  Is any peripheral that receives data from a computer, usually for display, projection, or physical reproduction. Output unit accepts the results produced by the computer which are in coded form and it converts these coded results to a human- readable form.
• Monitor

  • Is an output device that displays video images and text. A monitor is made up of circuitry, a screen, a power supply, buttons to adjust screen settings, and casing that holds all of these components. Based on the technology used, a monitor is classified into two types. They are Cathode Ray Tube (CRT) monitor and Liquid Crystal Display (LCD) monitor.
• Printer


  • Is an output device that prints paper documents. This includes text documents, images, or a combination of both. The different types of printers are Dot Matrix Printers, Inkjet Printer and Laser Printer.
• Touch Screen


  • Is a display device that allows the user to interact with a computer by using their finger or stylus. A touchscreen is a display screen that is sensitive to human touch.
• Plotter


  • Is very large in size and is used to produce graphical output on papers. It uses single or multi-color pens to draw pictures as blueprint, posters etc.
• Storage Devices


  Are used to save data and information
• Hard Disk


  • Is made up of a metal disk and coated with a metal oxide used to store the bulk of data. These disks can store more information than floppy disks, up to tens or hundreds of gigabytes.
• CD-ROM: Compact disk-read-only


  • Memory is a read write disk. It can store a large amount of data which can b distributed to a large number of users. It is inexpensive and fast but its access time is longer than that of a magnetic disk.
• DVD (Digital Versatile Disc)


  • Is an optical storage disc similar to CD-ROM, as this is double sided with dual-layer disc and can hold 4.7 GB of data.
• Blue-ray disks


  • Used to store more than 25 GB of data with a very high speed in less amount of time. A single layer of BD can store 13 hours of video whereas double layer BD can store more than 20 hours of video.
• Case


  • Physically mount and contain all of the actual components inside of a computer
• Power Supply


  • Connect all of the parts of a computer to electrical power
• Fan


  Used for active cooling
• Motherboard


  • A printed circuit board that is the foundation of a computer
  • Allocates power
  • Allows communication to the CPU, RAM, etc.
• Drives


  The devices used for long-term storage of information (Hard disk)
• Cards


  • Connect and communicate with various input and output devices
• RAM


  The short-term memory that is used to store documents
• Processor


  • The brain of a computer system
  • Controls the software and hardware
• CPU


  Central Processing Unit