A domain name can be used to identify a single IP address or group of IP addresses. Domain names have two parts that are separated by a dot, such as talksindepth.com. A domain name is used as part of a URL to identify a website.
A domain name can be any combination of letters and numbers, hyphen and it can be used in combination with the various domain name extensions, such as .com, .net .org and more. The part that follows the dot is the top level domain (TLD), or group to which the domain name belongs. For example, .gov is the TLD for government domains.
We humans can use domain names to communicate, While computers require IP addresses to locate one another. The Domain Name System, or DNS [D-N-S], takes domain names — the kind of web addresses (URL) that people understand, like xyz.com — and translates them into IP addresses that computers need to communicate one another.