Technically speaking, a domain name is just the plaintext way to write an IP Address. All websites and internet-connected resources use a URL or unique name which is always a long number known as an IP Address. The domain name is simply the plaintext version of the URL that is mapped to a specific IP Address.
For example, the domain name for WordPress is “www.WordPress.org,” but its IP address is 18.104.22.168. You could type in either “www.WordPress.org” or “22.214.171.124” into your browser, and both addresses will take you to the same resource (the WordPress website, in this case).
In order acquire a domain name, you have to obtain it from an official domain registrar managed by the Internet Corporation for Assigned Names and Numbers (ICANN). These registrars sell domain names. The domain name must then be registered with two nameservers which are responsible for associating your site’s unique IP Address with its plaintext URL address or domain name.
Note: Some WordPress web hosting companies also provide free domain name registration. But it’s important to remember that the company providing the domain name does not necessarily have to be the same one that is hosting your website’s files.
Most people are familiar with domain names that end in “.com” or “.org”, but there are thousands of other kinds of domain names. Each country and territory has its own domain name extension, and there are also special domain name extensions like “.edu” for educational institutions and “.biz” for businesses.
Once you own a domain name, WordPress will automatically use this to create unique URLs known as permalinks for your posts, pages, media, and other publicly available files. WordPress will use the domain name as the beginning of the URL, appending other relevant information such as the title of the post and the date that it was written.