Introduction

Flowchart is a pictorial way to express algorithm or process. So, instead of writing down our algorithm in some programming language like C, C++, Java, C#, PHP, Python, Ruby etc. we use flowchart to express our algorithm which gives us a general view about the algorithm.

Flowchart as the name indicates, is about the flow of execution of our algorithm.

Important terms

Before we proceed, there are some important terms that we must understand in order to fully visualize the flowchart topic.

Procedure

A procedure is a finite sequence of well-defined instructions, each of which can be carried out in a finite amount of time.

By finite, it means we can conut the number of instructions in the Procedure. And by well-defined we mean to say that there is no ambiguity in the instruction.

Algorithm

An algorithm is a step-by-step procedure (well-defined instructions) to solve a given problem.

For instance, the algorithm to find the sum of two numbers is

1. Take two numbers
2. Add the numbers
3. Display the result

Or the algorithm to make a cup of Darjeeling tea is

1. Take 1 tea spoon of Darjeeling tea leaves and place it inside a tea pot
2. Pour some water
3. Cover the pot with the lid and boil
4. Let it brew for about 3 to 5 minutes
5. Stain the tea in a cup and serve

Flowchart

A flowchart is a type of diagram that represents an algorithm or process.

Answer this simple question

How will you log in to your facebook account?

You may answer

• Using Desktop
• Laptop
• Tablet
• Smart phone - Android, iPhone, Windows
• Using friend's computer
• From Internet Cafe
• College Campus

etc...

All the options are absolutely correct. Lets move on to the next question.

Write an algorithm to log in to your facebook account?

Remember! An algorithm is a step-by-step procedure to solve a given problem.

You can write the algorithm to log into your facebook account in simple English as:

1. Go to www.facebook.com
2. Enter Email ID and Password
3. Click on Log In button

Yes, you guessed it right. Its really very simple and easy to write algorithm. All you have to do is write the correct steps in correct sequence.

Basic symbols used in Flowchart

There are 6 basic symbols commonly used in Flowchart.

1	Terminal		Indicates the starting or ending of the algorithm. We draw a terminal symbol and write START inside it to indicate the start of the flowchart. Similarly, we draw a terminal symbol and write STOP inside it to indicate the end of the flowchart.
2	Input/Output		Use for Input/Output (I/O) operation i.e. taking input and showing output.
3	Process		Indicates any type of internal operations like initialization, calculation etc.
4	Decision		Use for asking questions that can have either TRUE or FALSE (YES or NO) as an answer. Example: Are you online? Answer can be either YES or NO
5	Connector		Connectors are used to connect breaks in the flowchart. If a flowchart takes more than one page, then to connect the flowchart between pages we use the connector.
6	Control Flow		Show direction of flow.

Flowchart Rules

• Flowchart is generally drawn from top to bottom
• All boxes of flowchart must be connected with arrow.
• All flowchart start with a Terminal or Process symbol.
• Decision symbol have 2 exit points, one for YES (TRUE) and another for NO (FALSE).