Testing is the process that you use to ensure that the script you have written actually does what it is supposed to do.Without testing you have no way to tell whether the script actually works.If it were possible to write scripts perfectly so that they always did exactly what they are supposed to do first time and every time then there'd be no need to test. Exen the experts can't write perfect code all the time though and so we need to test all our scripts in order to locate and fix any errors.

What is testing efficiency and how does it work?