DNS, or the Domain Name System, is one of the core systems that makes the internet usable. It translates human-readable domain names into the information computers need to locate websites and other internet services.
You usually do not notice DNS when everything is working correctly. When something is misconfigured, however, DNS can quickly become one of the most confusing parts of running a website.
DNS is a distributed naming system used to associate domain names with internet services. Instead of requiring visitors to remember an IP address, DNS allows them to use a domain such as gaugehosting.com.
DNS can provide information for websites, email, verification systems, subdomains, and many other services.
When you enter a domain name into a browser, several things can happen before the website appears.
Modern browsers and operating systems cache DNS information, so not every visit requires a complete DNS lookup.
Nameservers are DNS servers that provide authoritative information for a domain. When a domain is delegated to a particular set of nameservers, those servers become responsible for answering DNS queries for the domain’s zone.
Hosting providers, domain registrars, and dedicated DNS providers may all operate nameservers.
An A record maps a hostname to an IPv4 address. For example, a domain’s A record can point a website hostname to the IPv4 address of its web server.
An AAAA record performs a similar function for IPv6 addresses.
A CNAME, or canonical name record, aliases one hostname to another hostname. This is commonly used for subdomains or services where the destination may change independently.
MX records identify the mail servers responsible for receiving email for a domain.
For example, your website could be hosted on one server while your email is handled by an entirely different provider. MX records make that separation possible.
TXT records contain text data used for a variety of purposes. They are commonly used for domain verification and email authentication technologies such as SPF, DKIM-related configuration, and DMARC policies.
You will often hear people say that a DNS change needs time to “propagate.” The more precise explanation is that DNS resolvers cache responses according to their TTL values.
If you change a record, some resolvers may continue returning the previous cached value until that cache expires. This is why a DNS change can appear to work from one location before it works from another.
TTL stands for Time to Live. It specifies how long a DNS response may be cached by a resolver.
A shorter TTL can allow changes to be recognized sooner after the existing cache expires, while a longer TTL can reduce the frequency of DNS queries. TTL should be considered when planning website migrations or other significant DNS changes.
Many website connection problems are caused by incorrect DNS records or delegation. Common examples include:
Technical users can inspect DNS directly from the command line. On Linux and macOS, tools such as dig can query DNS records.
dig example.com A
dig example.com MX
dig example.com TXTYou can also query a specific DNS resolver when troubleshooting differences between networks.
DNS is what connects your domain name to the infrastructure providing your website. Your hosting provider may supply DNS management or nameservers, but the domain’s registrar can be completely separate from the hosting provider.
This is why changing hosting does not necessarily require transferring your domain registration. In many cases, you simply update the DNS records or nameservers to point toward the new service.
For an introduction to the relationship between domains and hosting, see Domain Names vs Web Hosting: What’s the Difference?.
GaugeHosting provides hosting infrastructure for websites and related services. Understanding DNS makes it easier to connect domains, troubleshoot website access, configure subdomains, and manage email services.
DNS is essentially the directory system that helps the internet locate services by name. A records, AAAA records, CNAME records, MX records, TXT records, and nameserver delegation each perform different jobs.
Once you understand those basic components, DNS stops being mysterious. It becomes another manageable part of operating a website.