A flowchart is a common form of a diagram, which is used to represent an algorithm program or a process. The algorithm program is a set of rules, which are used to solve a specific problem.
A process created using flowchart symbols can be as simple as starting from office, dropping children to school, and end of the process by reaching office. The example of a process was a very simple one, however the diagram is generally used for processes, which involve a problem and multiple solutions.
It can be very complex with multiple solutions, and more than one end; but the starting point is only one, and then, it branches out in different stages. To branch out the different stages arrows are used, there are basically 3 types of arrows used, which can be seen in the figure.
The Rounded Rectangle
It represents the start or end of a program or process. Many times, circles or ovals are also used to represent the start and end of a process.
A parallelogram is used to denote input or output of information. For example, the input can be written as the input of a picture in the computer by scanning, the process can be editing it, and the output can print of the new edited picture.
It is a very commonly-used figure. It is used to represent the processing steps in a program or process.
The Diamond (Rhombus )
The diamond is used to denote a condition or decision. It mostly contains a true or false test or a yes and no question. It has two arrows coming out of it, typically one arrow at the bottom and one arrow pointing in the right direction. Either one of the arrow can be pointing to a yes or no situation. While drawing, these arrows are always labeled.
It is also known as a decision symbol, and it is used to indicate the beginning of a repetition pattern or structure in a process.
The Double-Lined Rectangle
It is not used very often. It is used at a point in an algorithm, where a sub program is introduced.
They help to denote the flow of control, which means they point towards one symbol to another, meaning the pass of the control. Arrows with a circle are used to connect the diagram between pages. The arrow with the circle is used if the chart is very long, or starts in the middle of a page and continues on the next page.
Study some examples of various such diagrams to understand the use of the symbols better, and then take assignments of programs or processes to draw the diagrams. There are many software that allow you to create them.
All you have to do is drag and drop the various symbols, and use the arrows to connect the diagram. The software also allows you to type in them, edit the text, and alter their placement.