You already know how to add two numbers. But how do you draw the process? Flowcharts provide a visual language to map out the steps of any procedure, from a simple calculation to a complex software program. To ensure everyone reads this language the same way, we use a standard set of symbols.

These symbols aren't arbitrary; they follow an international standard called ISO 5807 to maintain clarity and consistency. Think of them as the basic vocabulary for describing logic. Let's look at the core symbols needed to map out our sum calculation program.

Every process needs a clear beginning and end. In flowcharting, we use an oval shape, called the Terminal symbol, to mark these points. You'll always have one 'Start' terminal and one 'End' terminal. It’s a simple rule that makes any flowchart's scope immediately obvious.

Next, we need to handle data. The Input/Output (I/O) symbol, a parallelogram, is used whenever the program receives external data or displays information. For our sum calculator, we would use one I/O block to 'Read Number A' and another to 'Read Number B'. We'd use a third one at the end to 'Display Sum'.

This is different from the Process block. Represented by a rectangle, this symbol is for actions and calculations the program performs internally. This is the 'doing' part. Adding Number A and Number B together is a process. The key distinction is between interacting with the outside world (parallelogram) and thinking for itself (rectangle).

Finally, we connect these symbols with Flowlines. These are simple arrows that show the direction of logic, guiding the reader from one step to the next. The flow almost always moves from top to bottom or left to right.

Let's visualise the complete flowchart for adding two numbers.

Notice the sequence: the process is bounded by terminals, data flows in and out via parallelograms, and the actual calculation happens in a rectangle. Every step is unambiguous. This simple structure is the foundation for mapping any process, no matter how complex.