What is Function ?

•A function is a block of code which only runs when it is called.

•In python you can define function using def keyword.

Why function is used ?

•You use functions in programming to bundle a set of instructions that you want to use repeatedly or that, because of their complexity, are better self-contained in a sub-program and called when needed.

What is Recursion ?

•Recursion is a common mathematical and programming concept. It means that a function calls itself.

Why Pass statement is used ?

•function definitions cannot be empty, but if you for some reason have a function definition with no content, put in the pass statement to avoid getting an error.