Flowcharts

What is Flowcharts?

Within Computer Science, which covers algorithms, programming, data, networks, hardware and safe, responsible use of technology, this topic explains Flowcharts. Computing topics explain how software, hardware and data work, with diagrams and models that show each step in order.

Check that you can explain Flowcharts in your own words and give one example from everyday life. If you can do that, you have understood the core idea.

Understanding Flowcharts helps you design, test and explain programs, websites and systems, from small projects to exam questions.

Flowcharts in detail

A flowchart is a diagram that shows the steps of an algorithm using standard symbols joined by arrows. The oval (terminator) marks the start and end, a parallelogram shows input or output, a rectangle shows a process or calculation and a diamond shows a decision with yes/no branches.

Flow lines show the order, and loops return to an earlier step. Flowcharts make logic easy to see, help plan programs, and help others understand them. To trace one, follow the arrows with sample values, recording the changes. Keep them simple and labelled, with a single start and clear end points.

How the interactive helps you understand Flowcharts

Click a step, or use the Previous and Next buttons, to move through the sequence one stage at a time. Auto-play moves on for you.

Before you change anything, predict the result. Then change one value at a time and check whether your prediction was right. This is a quick way to build a correct mental model of Flowcharts.

Real-life uses and examples

• Recognise Flowcharts in an app or device you use every day.
• Apply Flowcharts when you design a small program, website or spreadsheet.
• Explain Flowcharts to someone new to computing by comparing it to a familiar process.

Common mistakes to avoid

• Using the term without being able to say what the computer actually does.
• Testing only the normal case and forgetting the edge cases.
• Learning the definition without testing it. Use the quiz and the interactive to check that you can apply the idea.