A flowchart is a graphical representation of the steps needed for solving a problem or performing a task.
Every step in the solution (or task) must be listed…take nothing for granted. For example, if you were listing the steps involved in entering a locked room, you would have to list the step of stopping at the door, even though anyone would know that.
The steps must be listed in a particular order…the order in which they must be performed. For example, you cannot insert the key in the lock until you have chosen the correct key from your key ring.
Therefore, a flowchart is not only a pictorial representation of instructions (or steps), but it indicates every step in its proper order.
The symbols in a flowchart use different shapes for different types of instructions. It is the same principle as is used for highway signs throughout the world. An octagon always means STOP, an inverted triangle for GIVE WAY, and a diamond indicates some kind of WARNING. Below are examples of the most common type of flowchart symbols.