CORS, Cross-Origin Resource Sharing: Allowing Cross-Domain Communication

Cross-Origin Resource Sharing (CORS) is an essential mechanism that enables communication between clients and servers, even if they are on different domains. Normally, JavaScript applications running in the browser can only access HTTP resources on the same domain that serves them. However, CORS provides a way to allow connections to other servers. By default, certain resources like images, scripts, and styles can be loaded from different origins. However, requests made using XHR or Fetch to a different domain, subdomain, port, or protocol will fail unless the server implements a CORS policy....