What is icann in hosting business?

Some registrar say that they are an ICANN accredited registrar. What is its means? All top level domain registrars are issued directly by ICANN (The Internet Corporation for Assigned Names and Numbers). that approves they're qualifying toplevel domain registrar instead reseller etc. That just means that they handle the registration directly, and they don't use a reseller to do it. Think it like the central government of the domain world. That is the way I see it at least. By the way, it is one of the questions on HE.Net's IPV6 certification test, so make sure you get the answer right if you want to take that one. ICANN coordinates domain name registrars which in the most cases do not provide web hosting.
If you see web hosting company offer domain name registeration 99% that is being offered as resellers. Most web hosting companies deal with registrars not with ICANN. Domain name registrars pays fee to Icann and if you have a problem with your domain name which your domain name registrar can't solve you always can get in touch with ICANN and ask to help you. For Reseller domain Which is ICANN Accredited, it is means they are qualifying could register the domain directly to ICANN.

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