DNS: names for internet addresses — Computing, 11–13
Discover how a readable website name is matched to the numerical address of a computer. Computing, 11–13 years.
A phone book for websites
DNS stands for Domain Name System. When you type a name such as example.com, DNS helps find the numerical internet address of the computer serving that site. You remember words more easily than numbers, so DNS connects a friendly name to a machine’s address.
The problem it solves
Computers need numerical addresses to send information, but people do not want to memorise a new number for every site. Before systems like DNS, finding a machine was much less convenient. DNS provides a shared naming system, so a site can keep a memorable name even if its underlying address changes.
Following a web address
Imagine typing school.example into a browser. First, the browser asks a DNS resolver for the address. The resolver may already know that the name points to 203.0.113.8; if not, it asks other DNS servers and saves the answer briefly. The browser then contacts that numerical address to request the page.
DNS is not the website
A reasonable mistake is to think DNS contains the whole website, because the page appears after the lookup. It does not store the articles, pictures, or videos; it mainly helps find an address. If DNS is unavailable, a site may still be running, but your browser may not know where to ask for it.
Where it appears
Every time you open a named website, send email to a domain, or use an app that contacts a service by name, DNS may be involved. It also helps companies move a service to a new computer without changing the name people use. When a site says it cannot be found, DNS is one possible place to investigate.
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