DNS or the Domain Name System is an integral part of the Internet. It refers to a system of computers and databases on the Internet that are responsible for translating a Domain Name into an IP (Internet Protocol) address.

Because humans find words much easier to remember than numbers, domain names were invented to make it easier for people to remember and access various computers connected to the internet. A domain name is a lot easier for most people to remember than a series of numbers. For example, it's much easier to remember www.microsoft.com than the IP address 207.46.199.30.

A Domain Name Server (also abbreviated to DNS) makes each domain eg: 'www.microsoft.com' resolve to the machine address eg: 207.46.199.30 when you type it into a web browser. The authoritative name server, that is, the name server the domain is delegated to, contains a set of instructions which determine how the domain should behave. This set of instructions is called a zone file.

Most ISPs run their own domain name servers (DNS), so the resolution of a domain can differ based on this. A particular server may have cached information that is no longer accurate, or might not be able to contact the authorative name server if there is a routing problem. This is what is meant by propagation delays and why changing the location of your domain name can take some time to be recognised throughout the internet.

In the context of your service with ProExe, you will be required to delegate your domain to a DNS host in order to get your domain to resolve to an IP address.