Cross Origin Resource Sharing (CORS) - CheetSheet

To understand CORS , I felt this is one of the best information, but uses python as back end,

This is example for configuring CORS in .net Rest API 

With Block diagram and use case , here is an example 

CORS in Azure API Management and other apis refer

Another good article on the CORS usage.

Restrict or Allow CORS using the policy in REST API like this.

To Set CORS for any Service in Azure, Go to the Service, search for CORS and set the Allowed Origin,  Allowed methods and allowed header.

•  Allowed Origin points to the URL which can be allowed.
•  Allowed Methods will indicate the REST Api methods allowed for that URL. 
• Allowed Headers will indicate the headers allowed.