DNS registrar is a company that is accredited by the Internet Corporation for Assigned Names and Numbers (ICANN) to sell domain names to the public. They are responsible for managing the domain name registration,renewal, and transfer processes.
Once you purchased from a DNS registrar, you become a registrant, or the person or company that owns the domain name. The registrant has the right to use the domain name for the specified period of time and can transfer the domain name to another registrar if they wish. So you dont actually own the domain, but rent it for a period of time, usually one year. You can renew the domain name before it expires to continue using it. If you do not renew the domain name, it will be released back to the public and can be registered by someone else.
You should note that DNS registrars are different from DNS registries. DNS registries are responsible for managing the top-level domain (TLD) and the root zone file, while DNS registrars are responsible for selling domain names to the public and managing the domain name registration process. The top-level domain (TLD) is the last part of a domain name, such as .com, .net, or .org. The root zone file is a database that contains information about all the TLDs and their associated name servers. The root zone file is maintained by the Internet Assigned Numbers Authority (IANA) and is used by the DNS to resolve domain names to IP addresses.
Most DNS registrars are also DNS providers, which means that you can configure the DNS records for your domain name through the registrar’s control panel. But thats not always the case, you can use a different DNS provider to manage the DNS records for your domain name even if you registered the domain name with a different registrar.
Common DNS registrars include GoDaddy, Namecheap, and Google Domains. When choosing a registrar, it is important to consider factors such as price, customer support, and ease of use. Some registrars also offer additional services such as web hosting, email hosting, and SSL certificates.