A Multi-Domain SSL certificate, also known as a Subject Alternative Name (SAN) certificate or Unified Communications Certificate (UCC), is a type of SSL/TLS certificate that allows you to secure multiple domain names (fully qualified domain names or FQDNs) with a single certificate. Here’s how Multi-Domain SSL certificates work and why they’re useful:

  1. Multiple Domain Support: Multi-Domain SSL certificates enable you to secure several domain names (primary domain and additional domains) with one certificate. These additional domains can include variations of your primary domain, different domain names, or even IP addresses.

  2. Cost Efficiency: Instead of purchasing separate SSL certificates for each domain or subdomain, a Multi-Domain SSL certificate allows you to secure all your domains with a single certificate. This can be a cost-effective solution, especially for businesses or organizations with multiple websites or online services.

  3. Simplified Management: With a Multi-Domain SSL certificate, you only need to manage one certificate for all your domains, simplifying certificate administration and reducing administrative overhead. This is particularly beneficial for organizations with a large number of domains or subdomains.

  4. Flexible Configuration: Multi-Domain SSL certificates offer flexibility in configuring which domains to secure. You can easily add or remove domains from the certificate as needed, making it adaptable to changes in your web infrastructure or domain portfolio.

  5. Encryption and Security: Like other SSL certificates, Multi-Domain SSL certificates provide encryption for data transmitted between the web server and users’ browsers. This encryption helps protect sensitive information such as login credentials, personal data, and financial transactions from interception by unauthorized parties.

  6. Browser Compatibility: Multi-Domain SSL certificates are widely supported by modern web browsers, ensuring that users can access your websites securely regardless of the browser they use. Users will see the padlock icon in the browser’s address bar, indicating that the connection is encrypted.

  7. Validation Levels: Multi-Domain SSL certificates can be issued with different validation levels, including Domain Validation (DV), Organization Validation (OV), and Extended Validation (EV), depending on your specific security requirements. You can choose the appropriate validation level based on your organization’s needs and preferences.

Overall, Multi-Domain SSL certificates offer a versatile solution for securing multiple domain names with a single certificate, providing convenience, cost savings, and robust encryption for your online assets.