It's the cyberspace address to your website.
Use Inphase domain search bar below to find your domain name.
It will take you to another window, showing if the name is available to register. If so, you can register it with Inphase from that page. If not, it will allow you to continue searching until you find a suitable name that is available.
Whereas the term domain means an area of ownership or influence, we can think of our domain name as our web space. And all web space is divided into groups. The entire Internet is divided into groups, i.e. name groups which are known as domains.
So the TLD (as com or net) forms a name group and your name forms a group within the TLD group. This grouping helps a browser find your domain name quickly as it goes to the right name group to find it, rather than searching through all the names on the Internet.
Domain names make the request for a particular website lightening fast.
Any device that communicates with the Internet (as a computer) uses an IP address to identify itself. IP addresses are made of a long series of numbers and dots which make them hard to remember. Your DNS (Domain Name System) identifies your domain name with your IP address. By doing that, your name can be used instead of the IP address to locate your website on the Internet.
The majority of people who startup an online business begin with finding a hosting plan and the plan chosen is usually determined by the cost of the plan. That way may be reasonable, but it's not practical. Inphase suggests another way.
Read More about How To Pick The Right Domain Name.