Definition
Just as you save a name like "Mom" or "Alex" in your contacts instead of a long string of digits, a domain name is an internet address made of words that stands in for the long numeric address (IP address) computers use, so people can remember and type it easily. It lets you find countless websites around the world without confusion.
A Friendly Name Tag for a Complicated Number
Almost nobody memorizes a friend's long phone number and dials it every time. You save the name in your phone's contacts and just tap the name to call.
The internet works the same way. Computers and servers originally find each other using long, complicated strings of numbers like `142.250.206.46`. This numeric home address on the internet is called an IP address. If you had to remember and type this long number every time you visited a favorite site, the internet would be a pain to use.
So people decided to give each address a name that is easy to read and remember, in English or in other languages. That name is the domain name. When you type `google.com` or `naver.com` into your browser and get right in, you have domain names acting as name tags to thank.
Read Backward, From the Right of the Dot (.)
A domain name is split into several parts by dots (.). It looks like you read it from the left, but in a computer network the scope gets narrower as you move from right to left, in a layered structure. It's a bit like writing country, city, and neighborhood in order on an envelope.
The piece at the far right, like `.kr`, `.com`, or `.org`, is called the top-level domain. It is the biggest fence, showing the country or the kind of organization. The part right before it, like `google` or `naver`, is the second-level domain, the unique name of each company.
The word at the far left, like `mail` or `blog`, is a subdomain that points to a specific service within that site. Because the dots divide the address into levels like this, hundreds of millions of websites around the world can keep their addresses organized without overlapping.
A Bit More Precisely
Typing a domain name into the address bar doesn't mean the computer understands those letters themselves. A computer can still only understand numeric IP addresses. So behind the scenes, a huge internet phone book called the DNS (Domain Name System) is constantly working, instantly translating the domain name into a numeric address.
Another interesting point is that a domain name is not land you can own forever. It is a lease you pay a fee to rent. You usually register the right to use it for a year at a time, up to 10 years at most, and pay for it. If you don't renew it even within the grace period after it expires, the right disappears and someone else can register that domain.
In the end, a domain name is a signboard that helps people get around the internet comfortably, and a precious bridge that smoothly connects the real communication network with human language.
Common misconceptions
Once you buy a domain name, it's yours for life.
A domain name is not owned forever like real estate. You rent the right to use it for a year or a few years at a time. If you don't renew it regularly, you lose that right.
Where you meet it
You type `naver.com` into the address bar instead of a hard-to-remember string of numbers to reach a portal site.
When you open a company or shop, you register an official website address ending in `.com` or `.co.kr` that matches your brand name.
In one sentence
A domain name is a text name tag on the internet that replaces a hard-to-remember numeric IP address with something people can read and remember easily.