What Is DNS and How Does It Work?
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DNS, the Domain Name System, translates human-readable domain names into information computers use to locate internet services. When someone visits a domain, DNS helps determine where the browser should send the request.
It is often compared with a phone book, but modern DNS does more than map one name to one address. A domain can have records for websites, mail servers, verification, service discovery, and other purposes.
Nameservers and DNS records
A domain’s nameservers identify the DNS service that is authoritative for its records. Inside that DNS zone, common record types include A records for IPv4 addresses, AAAA records for IPv6, CNAME records for aliases, MX records for mail routing, and TXT records for verification and policy information.
What happens when you change DNS?
DNS information is cached at several levels, so changes may not appear everywhere immediately. The record’s TTL influences how long resolvers may cache old information, although real-world behavior varies. This is why a site or email configuration can appear correct from one network while another still sees older values.
Why DNS matters for hosting
Moving a website often involves changing DNS so the domain points to a new hosting environment. Because DNS also affects email and verification records, copying or reviewing the complete zone before a migration helps avoid accidentally breaking unrelated services.
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Your ISP assigns DNS servers to connect you
Your ISP assigns DNS servers to connect you, and that is usually the default path for a home or small office network.
DNS connections speed up website loading times
DNS connections speed up website loading times, but only in a specific way. DNS does not make the raw transfer of files faster.
DNS servers translate domain names to computer hardware IP addresses
DNS servers do the quiet work behind every domain name. They take a name like example.com and return the IP address that points to the machine serving the site.