• Domain Name Service

dns
  1. Help Center
  2. Domain Name Service
  3. User Guide
  4. Overview
  5. Basic Concepts
  6. Domain Name Levels

Domain Name Levels

Domain names are classified into the following levels:

  • Root domain: . (a dot)
  • Top-level domain: for example, .com.net.org, and .cn
  • Second-level domain: subdomain names of the top-level domain names, such as example.comexample.net, and example.org
  • Third-level domain: subdomain names of the second-level domain names, such as abc.example.comabc.example.net, and abc.example.org
  • The next level domain names are similarly expanded by adding prefixes on the left of the previous-level domain names.
    NOTE:
    • A domain name is segmented using dots (.).
    • Each label can contain letters, digits, and hyphens (-) and cannot start or end with a hyphen.
    • A domain name label cannot exceed 63 characters.
    • A domain name is not case-sensitive and does not exceed 254 characters, including the dot added at the end by default.