Computer systems can be broken down into four fundamental things that they do as seen in the image to the right. A computer system takes in inputs (from humans or sensors), processes these inputs using code, then either stores the data, or outputs it to the user, or both.
In short, computers at their most fundamental level can be really quite simple.
Once we can define what a computer system is, we can then put most computer systems into two types: embedded and general purpose systems.
General purpose systems are computer systems which allow you to add extra software in order to perform additional tasks. Examples of these are desktops, laptops, tablets, and servers.
In contrast, embedded systems have a specific purpose that cannot be changed easily by adding new programmes, either because there isn’t an interface to do so or because the hardware has not been designed to perform another task.
You may not realise that many embedded systems are in fact computer systems at all. If you’ve ever used a microwave to heat food then you’ve used an embedded system – you input the time and setting, the microprocessor allows the system to cook for a set amount of time, and when the programme has ended a microphone plays a sound and the cooking ends.
Look around your house – how many other examples of embedded systems can you find. If you get stuck, remember to refer to the diagram.