Flow charts show what is going on in a program and how data flows around it. Flow charts can represent everyday processes, show decisions taken and the result of these decisions.
The diamond shape explains when there is a choice to make. The flow chart shows what happens depending on the decision made at this point. Flow charts visualise the results of decisions, showing what will happen in a program, and also when, for example an if statement, is required to make a decision.
Flow charts can be used to show iteration (repeating something).
In the above flow chart, the user is asked what their favourite subject is. If they answer 'Computing Science' they are told they are 'clearly very intelligent' and the program stops.
Any other answer results in the user being asked again. If the user does not enter 'Computing Science', the program will keep going round and round, asking them forever until they enter Computing Science.