The Same Origin Policy (SOP) is a fundamental security concept implemented by web browsers to restrict how documents or scripts loaded from one origin can interact with resources from another origin. An 'origin' is defined by the combination of protocol, domain, and port. SOP prevents malicious scripts on one page from accessing sensitive data on another site through the browser, thereby protecting users from cross-site attacks such as Cross-Site Scripting (XSS) and Cross-Site Request Forgery (CSRF). While SOP enhances security, it can also limit legitimate interactions between websites, which developers can address using mechanisms like Cross-Origin Resource Sharing (CORS).