Origin refers to the combination of a website’s protocol (such as HTTP or HTTPS), domain name, and port number. In the context of web development and internet security, the concept of origin is crucial for enforcing the Same-Origin Policy (SOP), which restricts how documents or scripts loaded from one origin can interact with resources from another. For example, https://example.com:443 is considered a different origin from http://example.com:80 or https://sub.example.com:443. This distinction helps protect users from certain types of cyber attacks, such as cross-site request forgery (CSRF) and cross-site scripting (XSS).