DNS
DNSDNS is the internet naming system that translates human-readable domain names into IP addresses and other records needed to route traffic to the right servers. It works through a hierarchy of authoritative name servers and caching resolvers, returning record types such as A, AAAA, CNAME, MX, and TXT. DNS settings control where a domain points and how email and verification behave.
How It Works
When someone enters a domain in a browser, a DNS resolver (often run by an ISP, enterprise network, or public DNS service) looks up the domain's records. If the answer is not already cached, the resolver queries the DNS hierarchy: it asks a root server which top-level domain (TLD) servers to use (like .com), then asks the TLD servers which authoritative name servers are responsible for the domain, and finally asks those authoritative servers for the specific record requested.
The authoritative server returns records such as A/AAAA (map a name to an IPv4/IPv6 address), CNAME (alias one name to another), MX (mail routing), TXT (verification and policies like SPF/DKIM/DMARC), and NS (delegation). Responses include a TTL (time to live) that controls how long resolvers cache the result. Changes to DNS do not update everywhere instantly; they roll out as caches expire and resolvers refresh.
Why It Matters for Web Hosting
DNS is the bridge between your domain registrar and your hosting plan: even the best server will not receive traffic if the domain points to the wrong place. When comparing hosting options, check whether the host provides DNS hosting, an easy zone editor, and support for common records (A/AAAA, CNAME, MX, TXT) and features like low TTL control, DNSSEC, and reliable nameservers. DNS quality affects uptime perception, migration smoothness, and email deliverability.
Common Use Cases
- Pointing a domain to a web server using A or AAAA records
- Connecting www to the root domain (or to a CDN) with CNAME records
- Routing email to the correct mail servers using MX records
- Verifying domain ownership and configuring email authentication with TXT (SPF, DKIM, DMARC)
- Delegating subdomains to different providers using NS records
- Managing migrations by adjusting TTL and switching records with minimal disruption
DNS vs Nameservers
DNS is the overall system of records and lookups that map names to services, while nameservers are the specific servers that host and answer for a domain's DNS zone. Setting nameservers at the registrar delegates control of your DNS to a provider; editing DNS records changes where the domain and its services actually point. In practice, you often change nameservers when moving DNS hosting, and change records when moving websites, email, or CDNs.