Understanding Computer Hardware & IT Concepts
Understanding Computer Hardware & IT Concepts
UPS (Uninterruptible Power Supply): A battery that automatically provides an electricity supply to allow the server to shut itself down properly if the main power supply fails.
Processor: The most important part of the computer. It processes data and controls the computer.
Memory:
- RAM (Random Access Memory): Holds the program instructions and the data that is being used by the processor.
- ROM (Read Only Memory): Holds the program instructions and settings required to start up the computer.
CPU: The combination of the processor and memory.
Input Devices: Keyboards, scanners, barcode readers, digital cameras, microphones, and video cameras.
Output Devices: Monitors, printers, plotters, loudspeakers, and headphones.
Storage Devices: Magnetic tape, floppy disks, hard disks, CD-ROMs, CD-R disks, CD-RW disks, DVDs, and MO disks.
Communications Device: A modem (modulator/demodulator) is used for converting digital signals to analog signals and vice versa. This allows a computer to be connected to the ordinary telephone system.
Bus: A set of connectors used for carrying signals between the different parts of a computer.
System Unit: Consists of a metal chassis enclosed in a flat desktop or a tower-shaped case.
Barcode Reader: An input device; a special type of scanner for reading barcodes (a set of printed bars of varying thickness that are used to identify a product).
Speed Traps and Related Technology
Speed Traps: Used to catch drivers that are breaking the official speed limit.
Microprocessor: Calculates the speed of the car from the changes in the radio waves and triggers an ordinary camera with a flashgun to take a photograph of the car if it was speeding.
OCR Software: Optical Character Recognition software that changes picture images of letters and numbers into digital form for use by a computer system.
Data Mining
Data Mining: Filtering through large amounts of raw data for useful information that gives businesses a competitive edge. This information is made up of meaningful patterns and trends that are already in the data but were previously unseen.
Storage Device Comparisons
- You can write to hard disks faster than optical disks.
- DVD-ROMs have a higher capacity than CD-ROMs.
- CD-ROM and CD-RW disks are both low priced.
- Removable drives and flash drives cost more than other storage media.
- The cost of a fixed hard disk is lower than a removable one.
- Both magnetic tapes and fixed hard disks can have very high capacities.
- DVD-RW disks are cheap, but removable hard disks are more expensive.
Component Functions
- RAM: Holds data read or written to it by the processor.
- Processor: Controls all the operations in a computer.
- Mouse: Controls the cursor.
- Clock: Controls the timing of signals in the computer.
- Flash Memory Key: Reads and writes to electronic chips on a card.
- Monitor: Displays the output from a computer on a screen.
- Keyboard: Inputs data through keys like a typewriter.
- DVD-ROM Drive: Reads DVD-ROMs.
- Cache: Provides extremely fast access for sections of a program and its data.
- ROM: Holds instructions which are needed to start up the computer.