ICT

ICT

1. is an abbreviation for...Information and Communication Technology The subject of ICT encompasses any technology that allows us to process data and to communicate.

   • data is simply any numbers, letters or symbols that can be entered into a computer system. examples: A, 20, DOG, 3.1415927, ABC123, +++
     • the values represent the ISBNs of books, the values now have a context. With context, they have meaning - they are now information.
     • Any data or instructions that are to be processed by the CPU must be placed into main memory
       • RAM is a volatile storage device. This means that if the computer’s power is turned off the contents of RAM disappear and are lost.
         • When a computer is in use, its RAM will contain… 1. The operating system software 2. The application software currently being used 3. Any data that is being processed

2. a system has 3 stages

   • 1. Something feeds into the system (the input) 2. The system does something with the input (the process) 3. The process gives a result (the output)

3. a computer is a device that stores and processes information according to a set of instructions.

   • A computer is an information processing system
     • the hardware is the physical parts of the computer system – the parts that you can touch and see.
       • Software is a collection of instructions that can be ‘run’ on a computer. These instructions tell the computer what to do. Software is not a physical thing
         • Central Processing Unit (CPU) The CPU is the 'brain' of the computer. It is the device that carries out software instructions
         • An operating system is a special piece of software that manages the general operation of a computer system:
       • the hardware of a computer is a fairly useless lump of plastic and metal!
   • For a computer system to be useful it has to consist of both hardware and software.
     • Operating systems that you may have heard of: • Windows XP • Windows Vista • Mac OS X • Linux The system that people use to interact with a computer (to give it commands, to see the results of those commands, etc.) is known as the user interface.
       • The system that people use to interact with a computer (to give it commands, to see the results of those commands, etc.) is known as the user interface. There are two that you need to be aware of: • Graphical User Interface (GUI) • Command-Line Interface (CLI)
         • A GUI is an interface built around visual (graphical) things
         • GUIs are quite easy to use due to the visual nature of the interface
     • A mainframe computer is a large computer, often used by large businesses, in government offices, or by universities.
       • Laptop Computer A 'laptop' computer is a light, compact and portable PC. Laptops contain a rechargeable battery
       • A palmtop computer is similar to a laptop computer, but smaller. It'ssmall enough to fit in the palm of your hand there is no room for a trackpad, so a touchscreen or tiny joystick is used instead.
       • A PDA is similar to a palmtop computer, except it is even morecompact, and typically has no keyboard, using a touchscreen for all data input

4. a system has 3 stages

5. The general name the extra devices is ‘peripheral devices’. They are usually categorised into input devices, output devices andstorage devices.

   • What Are Input Devices? Devices that pass data into the computer are known as input devices. A keyboard, a mouse and a webcam are all examples of input devices.
   • What Are Output Devices? Devices that take data from the computer are known as output devices. A monitor, a printer and a loudspeaker are all examples of output devices.
   • Secondary storage (sometimes called backing storage) is the name for all of the devices
     • A hard drive, a CD-ROM, a floppy disc and a USB memory stick are all examples of secondary storage devices. Secondary storage is non-volatile