One of the biggest misconceptions our users face is understanding the difference between a domain registrar and a DNS host. Understanding these differences is crucial to maintaining a reliable and fast website that’s available to all of your users....
Many different services are involved in getting a site from the machines that serve it to the browsers of its users. Among them are domain name registrars, DNS hosting, web hosting, content distribution networks, and the networking infrastructure that underlies them all.
It’s common among IT professionals to advise that at least some of these services are distributed among different providers. For example, a site’s hosting provider should not be the same as the registrar that they bought their domain name from. The reasons for this are straightforward: occasionally companies fail (especially low-price domain name registrars and web hosts) and each company may have different strengths. Separating the domain name registrar from the hosting provider ensures that the risks and benefits are spread across different companies, rather than concentrated in one.
Separating out the the elements involved in site hosting allows administrators to make informed decisions about the relative strengths of the providers of each. The best web hosting company is unlikely to be the company that offers the best available DNS hosting. The most reliable domain name registrars do not always have the most robust web hosting services.