Cross-origin Resource Sharing (CORS) is one of the basic security features built into browsers. CORS controls accessing resources from a HTML page in domains other than the original domain. It is particularly important for AJAX calls. Since RESTful services can be used as data provider to any AJAX call, you have to be able to control cross-origin access. By default services are not allowed to do CORS. You are going to learn how to enable it for Ensemble RESTful services.
The Resource Map class (the subclass of %CSP.REST) controls whether CORS is enabled.

