Business rules were introduced with Dynamics CRM 2013 to assist power users without any coding skills in creating validation rules. As such, they are a very powerful feature added to the system customizer's toolbox.

A lot of customizations include various validation rules. From field-level validation to showing or hiding form fields based on values selected in other fields, business rules allow power users to implement a variety of rules in a pseudocode format. No code is required, as the whole creation of business rules is wizard-based.

While this is a step in the right direction, business rules will not replace JavaScript completely. For complex validations and implementation of complicated rules, you will find that certain limitations require a JavaScript developer to be involved.

The main difference between workflows and business rules is the location where the process runs. Business rules are primarily meant as client-side logic, and the result is expected to directly and...