hardware

3. needed to convert digital data into electric currents that can drive motors, actuators and relays, for example.
6. screen on which the touch of a finger or stylus allows selection or manipulation of a screen image; they usually use capacitive or resistive technology.
10. storage of data in non-consecutive sectors;for example, due to editing and deletion of old data.
11. used in DVDs; uses two recording layers.
13. number of pixels in the horizontal and vertical directions on a television/computer screen.
14. type of touch screen technology. When a finger touches the screen, the glass layer touches the plastic layer, completing the circuit and causing a current to flow at that point.
15. storage media with no moving parts that relies on movement of electrons.
16. CDs, DVDs and Blu-rayTM discs that use laser light to read and write data.
17. needed to convert analogue data (read from sensors, for example) into a form understood by a computer.
18. type of ROM chip that can be programmed once.
21. primary memory unit that can only be read from.
22. high speed memory external to processor which stores data which the processor will need again.
23. type of RAM chip that uses flip-flops and does not need refreshing.
24. a type of EEPROM, particularly suited to use in drives such as SSDs, memory cards and memory sticks.

1. input device that reads physical data from its surroundings.
2. type of magnetic storage device that uses spinning disks.
4. a type of ROM chip that can be modified by the user, which can then be erased and written to repeatedly using pulsed voltages.
5. primary memory unit that can be written to and read from.
7. apparatus worn on the head that covers the eyes like a pair of goggles. It gives the user the ‘feeling of being there’ by immersing them totally in the virtual reality experience.
8. type of touch screen technology based on glass layers forming a capacitor, where fingers touching the screen cause a change in the electric field.
9. type of ROM that can be programmed more than once using ultraviolet (UV) light.
12. the lag in a system; for example, the time to find a track on a hard disk, which depends on the time taken for the disk to rotate around to its read-write head.
19. type of RAM chip that needs to be constantly refreshed.
20. uses movement of electrons between cathode and anode to produce an on-screen image. It generates its own light so no back lighting required.