DNS, which stands for Domain Name System, is one of the most important services that has been used for a long time. In a nutshell, it does translate the service names, for example, a website to an IP address. Azure provides DNS as a service by which you can host your domains in Azure, which will provide name translation using Microsoft Azure infrastructure with 99.99% availability SLA. At the time of writing, it does not support domain name purchasing.
In May 2015, Microsoft announced the public preview of Azure DNS at the Ignite conference. After that, the service was used by many customers who delivered great feedback that made the service more mature, and in September 2016 Microsoft announced the general availability of Azure DNS.