DNS is one of those technical terms that appears whenever you register a domain, move a website, set up email or change hosting. It can sound more complicated than it is, but the basic idea is simple.
DNS stands for Domain Name System. It helps browsers and mail servers find the right destination for a domain name.
Domains are easier than numbers
Computers use IP addresses to find servers on the internet. People use domain names because they are easier to remember.
When you type a website address into your browser, your device needs to find out which server is responsible for that domain. DNS is the system that helps make that connection.
You can think of it a little like an address book. You ask for a domain name and DNS helps point you toward the correct server address.
What happens when you visit a website?
When you enter a domain name, your browser checks whether it already knows where to go. If it does not, it asks DNS servers to help find the right record.
Once the correct address is found, the browser can connect to the web server and request the page. Most of this happens quietly in the background, often in a fraction of a second.
Common DNS records
Different DNS records do different jobs. A records point a domain or subdomain to an IPv4 address. AAAA records point to an IPv6 address. CNAME records point one name to another name.
MX records tell email where to go. TXT records are often used for verification and email authentication.
You do not need to memorise every record type, but it helps to know that websites and email can depend on different DNS settings.
Why DNS changes can take time
When DNS records change, the update may not appear everywhere immediately. DNS information is cached by different systems to make the internet faster and more efficient.
This delay is often called propagation. In many cases changes are visible fairly quickly, but it is sensible to allow time when moving hosting, changing email providers or launching a new site.
Why DNS matters
Incorrect DNS can make a website disappear, stop email from arriving or break important services such as verification, security and deliverability.
That is why DNS changes should be made carefully. If you are changing nameservers, moving hosting or editing email records, take a copy of the current settings first and only change the records you understand.
DNS may be invisible when everything is working, but it is one of the foundations your website and email rely on.