Difference between client script and user event script

Question

We use client script for client side validations purpose,what are the scenarios we use user event script for server side validations and what is the main purpose of user event script.

Answer 1

In short...

1. Client scripts are client side scripts (executed in your browser). These are what you would generally think about as standard JavaScript.
2. User event scripts are executed on these server. These run based on events that trigger them, but never as an immediate client side action. These run:
   • before a page loads (making changes to the record before the client receives it).
   • Before the record is submitted (making changes based on what was received back from the client).
   • After the record is submitted (making changed based on the final results of the record after it has been placed in the database).

Hope that helps. Here is the documentation for all of the script types, as well: SuiteScript 2.0 Script Types.