Domain IP address
It is worth understanding the difference between a domain name and an IP address. The IP address is a set of digits, like 18.104.22.168. This number doesn’t tell anything to a human and is very hard to memorize and use, but this is the only code which a machine can use.
The domain name is essentially a link to the IP address. When you type it in your browser, it activates a process of locating the page you need. A DNS server decodes it in order to find domain IP address. Then this address is used to retrieve the web page.
You may think about an IP address as an actual address of a web page, while the domain name is a kind of nickname for it. It just points to the IP address, allowing your system to find it.
If you know a domain, for example google.com, you can always find its IP address, and vise versa. There are many ways to check domain IP on the Internet, for example Whoer.net. This is a convenient tool to lookup domain IP and obtain useful information about it. Not only you can know the exact IP of some domain, but such information as country, city, timezone, etc.