What are the different types of variables in Postman? How and when to use them?

Dear People,

I hope you are all safe!

Today we are going to learn something in Postman which will be very helpful and save our time in most of the scenarios.

If you have worked on any programming language, you would have worked with variables with different scopes. They are nothing but placeholders to hold some value or result of some expressions. We have the same variable concept in Postman with few scopes.