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SLD - Glossary | MDN 1/3 https://developer.mozilla.org/en-US/docs/Glossary/SLD reference web, html, css, javascript, documentation 2026-05-05T05:43:46.755605+00:00 kb-cron

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  1. Glossary
  2. SLD

SLD

The Second Level Domain (SLD) is the part of the domain name that is located right before a Top Level Domain (TLD). For example, in mozilla.org the SLD is mozilla and the TLD is org. A domain name is not limited to a TLD and SLD. Additional subdomains can be created to provide additional information about various server functions or to delimit areas under the same domain. For example, www is a commonly used subdomain to indicate that the domain points to a web server. As another example, in developer.mozilla.org, the developer subdomain is used to specify that the subdomain contains the developer section of the Mozilla website.

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