What is DNS, and what is it not?
DNS stands for Domain Name System. It is the directory that maps a hostname to the address computers use. People type a name. Machines connect to an IPv4 or IPv6 number. Without that map, every site would be a string of digits.
DNS is not the domain you buy, and it is not the server that stores the site. You register the name through domain registration. Hosting is where the files and mailboxes live. DNS is the lookup that points the name at those services. It is also not a VPN: a VPN hides a path, while DNS only answers where a name should go.
- DNS maps a hostname to an IP address.
- Registering the name and hosting the site are separate from that map.
- DNS is not a VPN and does not hide traffic.
What happens in a DNS lookup?
You type the hostname. The browser asks the resolver set on the device, often the one the internet provider supplies. If that resolver already cached the answer, it returns the IP address and the page request can start.
If the cache is empty, the resolver asks a root server which top-level server handles the ending, such as .in or .com. That server names the authoritative nameservers for the domain. Those nameservers return the record, and the resolver hands the address back to the browser.
A public address such as 1.1.1.1 or 8.8.8.8 is only a resolver you can choose on a device. Choosing one does not add or change a record in the domain's zone.
Which DNS records does a site use?
Each DNS record is one row the authoritative server returns. The type says what the value means. A DNS CNAME is the record that stores another hostname instead of an IP address, and the lookup then follows that second name.
| Type | What it stores | What it is for |
|---|---|---|
| A | IPv4 address | The website |
| AAAA | IPv6 address | The same host when it also has IPv6 |
| CNAME | Another hostname | An alias such as www. Not on the bare domain |
| MX | A mail hostname | Where inbound mail is delivered |
| NS | A nameserver hostname | Which DNS host publishes the zone |
Use a CNAME for an alias such as www. Do not put a CNAME on the bare domain, and do not put it on a name that already has an A record. Mail uses an MX row whose value is a hostname, not an IP address. The fuller set, including TXT, is on DNS records explained.
- An A record stores IPv4 and an AAAA record stores IPv6.
- A CNAME stores another hostname and is not used on the bare domain.
- An MX record names the mail host. An NS record names the DNS host.
How is DNS different from the registrar?
The registrar is where the domain is registered and renewed. Nameservers are the hosts that publish the zone. DNS records are the rows inside that zone. A save in the registrar panel changes nothing when the nameservers point at a different DNS host.
To move the whole zone, change nameservers at the registrar. To change where the site or mail goes, edit records at the DNS host those nameservers already use. The website and the mail can live on different hosts: the A record sends the site, and the MX record sends the mail.
Why does a DNS change take time?
TTL is how many seconds a resolver may keep an answer. After you save a new record, anyone who cached the old one keeps it until that timer ends. A TTL of 3600 can leave the old address in place for an hour. You cannot clear every cache on the internet.
Lower the TTL a day before a planned move, make the edit, then raise it after a fresh lookup shows the new value. Your own panel can show the new row at once. Other networks update only when their copy expires, which is sometimes as long as 48 hours.
How do you check that DNS is working?
A panel save is not proof. Ask a resolver that did not just load the site, and compare the answer with the row you saved. You can check the live DNS records for that name and type.
- Write down the record type and the value you expect, such as the A record on the bare domain.
- Query that name from a network that is not the one you just edited on.
- The check worked when the answer matches the value you saved. A browser that still shows the old site only means a cache is still in use.
Frequently Asked Questions
What is DNS in simple words?
DNS is the Domain Name System. It turns a hostname into the IP address a browser uses to open a site, and it tells mail where to go. The domain name and the hosting server are separate from that lookup.
Is DNS the same as a domain name?
No. A domain name is the label you register, such as webji.in. DNS is the system that looks that label up and returns the records computers need to connect.
What is a DNS CNAME?
A CNAME is a DNS record that stores another hostname instead of an IP address. The lookup then follows that second name. Use it for an alias such as www, not on the bare domain, and not on a name that already has an A record.
What is the difference between nameservers and DNS records?
Nameservers are the hosts that publish the zone. DNS records are the rows inside that zone. Edit records only at the DNS host those nameservers point to. A change in any other panel is ignored.
How long does a DNS change take?
It follows the TTL already cached. That is often minutes to a few hours, and it can reach 48 hours when the old TTL was long. The panel can show the new value at once while other networks still have the old one.
How do I check my DNS?
Query the name and the record type from a network that did not just load the site. The check has worked when that answer matches the value you saved. A cached page is not a failed zone.