A diagram showing the symbols used in a flowchart.
Start and Stop symbols are used as a starting point for the diagram and exit point(s).
Process symbols are used for to indicate that a process is happening.
Decision symbols are used for when there are multiple out comes, two or more arrows should come out of the diagram and redirect you to another part of the diagram. Next to each arrow there should be a note saying what the out come is, e.g. 'Yes' near one arrow and 'No' near another.
Arrow symbols are used to indicate the flow of where you're meant to go next.
There are two types of control systems used for flow charts, Open-loop and Closed-loop.[1]
An open loop system is a system is a flow chart that is does not loop back to a previous part of the diagram, it can still have decision symbols as long as they do not go back to a stage that you've already been to.