Every server in the world that has access to internet has at least one IP address to a computer, this is like a phone number. An example of an IP address is 74.125.45.100.
Instead of having to remember a list of numbers, domain names allows us to assign a name to those numbers. Without domain names, you would have to enter an IP address every time you wanted to visit a website. For example, google.com is much easier than 74.125.45.100 right?
Domain names can contain letters, numbers, and hyphens. They can be hundreds of characters in the length, but the shorter,the better. So that it will be easy for everyone to remember.
In order for your computer to figure out what IP address to use for a domain name, it has to connect to a name server, also called a DNS server. That server connects to another server, which connects to another, and so on, until a server is encountered that knows the right IP address for the domain name.
When you purchase a domain name, you then tell the domain registrar that all request for an IP address for that domain name should be directed toward your hosting provider’s nameservers. Once you have informed your webhost the domain that you plan to use, they will configure their nameservers to give your domain name a specific IP address.