What is CORA? Why is it so important?

Cross-Origin Resource Sharing (CORS) is defined as the browser mechanism that involves controlled resources access granted outside the given domain. It can enable a web page to access the resource with a different domain. It is a relaxation of some policies associated with browsers implemented on the same origin.

CORS is important because it follows the same-origin policy by channeling XMLHttpRequest and fetching JavaScript to make URL calls in the same location where the script is running. Without CORS, there will be restrictions in accessing some critical resources that power the web.