Domain blocking is a cybersecurity technique used to prevent users from accessing specific websites or online services by restricting their domain names or internet addresses. Organizations, internet service providers, or individuals may implement domain blocking to protect against malicious sites, reduce distractions, enforce company policies, or comply with regulations. When a domain is blocked, attempts to visit the associated website are denied, often displaying a warning or error message. This method is commonly used to block phishing sites, adult content, or other unwanted online resources and can be managed through firewalls, DNS filtering, or browser settings.