Describe how digital systems interact through input and output devices, and how devices connect to each other to share data and services.

What this dot point is asking

WJEC asks you to describe how a digital system takes in data, acts on it and produces results, and how separate devices connect so they can share that data and use each other's services. This is the foundation of the Digital technology systems topic: before networks and the internet make sense, you need the input-process-output model and the idea that devices are increasingly connected.

The input - process - output model

Every digital system, from a phone to a washing machine, follows the same basic flow.

Input devices include keyboards, mice, touchscreens, microphones and sensors. Output devices include screens, speakers, printers and motors. The same data may be stored before, during or after processing.

Embedded systems

Many everyday objects contain a small computer dedicated to one job.

Embedded systems are everywhere precisely because they are cheap, reliable and dedicated: they do one task well rather than running general software like a laptop.

How devices connect

Modern systems rarely work alone; they connect to share data and use services.

This connectivity is the bridge to the rest of the topic: a network is simply many connected devices, and the internet is a vast network of networks.

Sharing data and services

The point of connection is that resources no longer have to be copied by hand.

Storage in the model

The basic model is input, process, output, but most systems also need to store data, and a strong answer mentions this. Storage holds the program the processor runs, the data being worked on, and the results that must be kept after the power is off. There are two broad kinds: temporary working memory (RAM), which holds data and programs while the system is running and is lost when power is removed, and permanent storage (such as a hard disk, SSD or memory card), which keeps data between uses. In a connected system, data may also be stored remotely in the cloud. Identifying where storage fits, between the input arriving and the output being produced, shows you understand that processing usually relies on data being held somewhere.

Why this matters

The input - process - output model is the lens for understanding every device in the specification, and embedded systems show that "computers" are far more widespread than laptops and phones. Connection is the idea that turns isolated devices into networks: once you see that sharing data automatically saves time and enables automation, the benefits and risks of networks, the internet and cloud services all follow. It also sets up the security topic, because anything connected can potentially be attacked.