Domain name registrar details are associated with every domain name and can often be useful to know.
Checking the registrar of a domain name is easy, you enter the domain name into the whatsmydns.net domain name registrar lookup tool and the name of the registrar will be shown.
A domain name registrar is the company responsible for managing the registration of a domain name. Only certain registrars are permitted to handle the registration of certain domain names depending on local jurisdictions, particularly for country specific domain names. Many countries have strict rules over who is permitted to have certain names, particular rules may be in place for businesses, charities and non-profits (eg .org) as well as government domains (eg .gov).
It can be useful to know who the registrar of a domain name is in order to manage the registration status of that domain name. Domain names typically need to have a renewal fee paid yearly so knowing who the registrar is important to know.
In many cases domain name registrars also manage DNS records for a domain name, so in order to make DNS changes you need to know who the registrar is.
They can in many cases do. However, it is not required. Domain names can have their name servers (NS records) directed to third-party DNS hosting providers which can also manage DNS records.
Any domain name can have their registrar checked.
Some examples: google.com, wikipedia.org, apple.com, youtube.com, amazon.com
