2. What is an embedded system?

An embedded system performs a single task within a larger piece of equipment. For example a DVD player will have an embedded computer to handle all of the hardware and input/output. You don't need to install an entire operating system to get your DVDs to play.

Embedded computers control a system, but often require additional hardware.

For example, it may take in inputs from specialised sensors. The computer processes those inputs, and then produces an output that requires some physical action, such as spinning up or ejecting a DVD.

These physical actions are carried out by actuators.

Once the actuators have carried out their task, they send data back to the embedded computer, which decides what to do next. This is called 'negative feedback'.

Embedded computers are often built as a single unit, with everything mounted on a printed circuit board. RAM, ROM, CPU, Clock and connectors are all pre-installed.