What does DNS stand for? In networking, the letters mean Domain Name System, the service that translates a name people can remember, such as a website address, into the numeric IP address a computer needs to reach the right server. People often call it the phone book of the internet.
Every time you open a page, send an email or use an app that goes online, your device quietly asks a DNS server for an address. The lookup usually takes a fraction of a second, which is why most people never notice it until it breaks.
Quick facts
Stands for
Domain Name SystemType
Initialism, said D N SJob
Turns names into IP addressesStarted
Early 1980s, as the internet grewDefault port
53Other meaning
Did not start, in race resultsNot to be confused with
DHCP, which hands out addresses
What does DNS stand for, and why the name fits
Each part of the name has a job:
- Domain: a named area of the internet, such as a site name and its ending, like .gov or .edu.
- Name: the human friendly label you type.
- System: a worldwide network of servers that share the work.
Before DNS, networked computers kept a single shared list of names and numbers, and every machine had to download fresh copies. As the network grew, that list could not keep up, so a spread out, layered system replaced it. Spoken as three letters, it counts as an initialism, a term our acronym basics page unpacks.
How a DNS lookup works, step by step
- You type a site name into your browser.
- Your device checks its own memory, called a cache, for a recent answer.
- If it has none, it asks a resolver, usually run by your internet provider, your workplace or a public service.
- The resolver asks a root server, which points it to the servers for the ending, such as .com.
- Those servers point to the site's authoritative server, which holds the real record.
- The address comes back, gets cached for a set time, and your browser connects.
The address itself is an IP address, either a short IPv4 number or a longer IPv6 one.
DNS records you may see
| Record | What it holds |
|---|---|
| A | An IPv4 address for the name |
| AAAA | An IPv6 address |
| CNAME | An alias that points one name to another |
| MX | The mail server for email to that domain |
| TXT | Text notes, often used to prove ownership or fight spam |
| NS | Which name servers are in charge of the domain |
If you set up a small business site, the host may tell you to "update your DNS." That means changing these records in the account where you registered the name.
DNS meaning in everyday tech problems
The term often shows up when something goes wrong.
Error on screen: "DNS server not responding." Your device reached the network, but the address lookup failed, so it cannot find the site. Restarting the router or switching to a different DNS server often fixes it.
- Flush DNS: clear the saved answers on your computer so it asks again.
- Propagation: the wait, from minutes to a day or two, while servers around the world pick up a changed record.
- DNS filtering: a home or school network blocks certain sites by refusing to look them up.
Other things DNS can mean
Outside computers, DNS has a common sports use. In a race result table, DNS means did not start: the runner or driver signed up but was not at the starting line. It sits beside DNF (did not finish) and DQ (disqualified).
In medical notes the letters sometimes stand for deviated nasal septum, but that is a narrow use. If the setting is a router, a website or an IT ticket, the networking meaning is the one intended.
DNS vs similar network terms
- DNS vs IP: the IP address is the number; DNS is the service that finds it from a name.
- DNS vs DHCP: DHCP gives your device its own address when it joins a network, and often tells it which DNS server to use.
- DNS vs URL: a URL is the full web address; the domain name is the part DNS looks up.
- DNS vs VPN: a VPN tunnels your traffic, and many route your lookups through their own servers too.
Browse more terms like these in the tech acronyms section.
Questions people ask
What is the DNS full form?
The full form is Domain Name System. It is the set of servers that matches names to IP addresses across the internet.
What does DNS stand for in networking?
It stands for Domain Name System. In a network it is the service a device asks to find the numeric address behind a host name.
Is the DNS acronym said as a word?
No. People say the letters, "dee en ess." That makes it an initialism, though many people call it an acronym anyway.
What does it mean to change my DNS server?
It means telling your device or router to ask a different resolver for addresses. People do this to fix lookup errors, add filtering or try a faster service.
What does DNS mean in a race?
In sports results, DNS means did not start. The athlete was entered but did not begin the event.