Input and output devices, sensors and data storage

Learning objectives

Describe the operation of input devices including barcode scanners, QR code scanners, digital cameras, keyboards, microphones, touch screens and two-dimensional and three-dimensional scanners

Describe the operation of output devices including inkjet, laser and three-dimensional printers, LCD and LED displays, speakers, actuators and projectors

Name the sensor suited to a given application, choosing from the fourteen the syllabus lists — acoustic, accelerometer, flow, gas, humidity, infra-red, level, light, magnetic field, moisture, pH, pressure, proximity and temperature — and state the physical quantity each one measures

Compare primary storage with secondary storage, state the purpose of RAM and ROM, and explain why RAM is described as volatile

Describe how magnetic, solid state and optical storage each record data, and compare them on capacity, speed of access, portability and durability

Explain the purpose of virtual memory and of cloud storage, and state the benefits and the drawbacks of keeping data in the cloud rather than on local media