Intro to Scripts
A preprocessor script is a code snippet that is executed before the request is sent. This is useful when you want to include a timestamp in the request header or send a random alphanumeric string in the URL parameters.
Postprocessor script is a code snippet that is executed after the request has been sent. It is mainly used to assert whether the result returned by the request is correct or not, write the result data returned by the request to environment variables, etc.
Public scripts are designed to re-use scripts and avoid repetitions of the same scripts in different places.
Script API Reference