DNS stands for Domain Name System. It is the system that translates a domain name like yourbusiness.co.ke into the numeric IP address that computers actually use to locate your website or email server. Without DNS, you would have to remember a string of numbers instead of a domain name every time you wanted to visit a site or send an email.
How a DNS Lookup Works, Step by Step
Every time someone types your domain into a browser, a quick background process runs to find out where your website actually lives. It usually takes a fraction of a second.
- The visitor's browser checks whether it already has the answer saved from a recent visit (its local cache).
- If not, the request goes to a DNS resolver, usually run by the visitor's internet provider.
- The resolver asks your domain's nameservers, which host what's called your DNS zone, for the correct record.
- The nameservers reply with the matching DNS record, most often an A record pointing to an IP address.
- The browser uses that IP address to connect to the server and load your website.
The same lookup process happens for email. When someone sends a message to an address on your domain, their mail server looks up your domain's MX records to find out which server should receive it.
Tip: when you change a DNS record, the update does not reach every visitor instantly. Resolvers around the world cache the old answer for a while based on the record's TTL (time to live), which is why DNS changes can take time to show everywhere.
DNS Records vs Nameservers
These two terms are often confused, but they do different jobs:
- Nameservers tell the rest of the internet which company or hosting provider is in charge of answering DNS questions for your domain.
- DNS records are the actual answers stored inside that zone, such as which IP address your website uses or which server handles your email.
If you move your domain to a new host, you usually need to update your nameservers. If you are only changing one setting, such as where your email is delivered, you usually only need to edit a single DNS record. See What Is a Nameserver and Why Does It Matter? for more on that distinction.
Why DNS Matters for Your Business
DNS sits quietly behind almost everything that depends on your domain. If a record is missing or wrong, the practical effects are immediate: your website can become unreachable, your email can stop arriving, or visitors can end up on the wrong server entirely. Most hosting and email changes you make, such as pointing a domain to a new host or setting up a new mailbox, ultimately come down to adding or updating a DNS record correctly.
Understanding this one concept makes most other DNS-related tasks, such as adding records or checking propagation, much easier to follow.