A Domain Registrar is an entity that reserves domain names and assigns IP Addresses to them. A domain name is an alias used to easily find a website rather than needing to memorize and use IP addresses to access them.
This is not to be confused with the Domain Registry which manages and maintains domain names.
Why is this important?
When validating SSL Certificates, a form of domain control validation involves completing an Approver E-Mail. This can only be sent to E-Mails directly affiliated with the domain that is being validated. Often, this results in an E-Mail being sent to the domain’s “WHOIS Registrant E-Mail Address”. More specifically, this is the E-Mail address you provide when registering a domain name with the Domain Registrar.
This can be updated at any time by logging into your account with your Domain Registrar and updating your contact information, or you can contact them directly.
Who is my Domain Registrar?
You can find this out by completing a WHOIS search on your domain name. The official WHOIS database search for generic domains is through ICANN (The Internet Corporation for Assigned Names and Numbers).
A WHOIS search with ICANN will reveal your Domain Registrar and their website, allowing you to log in or make contact.