Why a domain name needs a lookup
When you enter a name such as www.example.com in a browser, your device needs an IP address to contact a server. The Domain Name System, or DNS, provides a way to look up that address. You can think of it as a distributed directory: different organizations maintain different parts of the naming system, rather than one server holding every answer.
A DNS lookup does not load the website. It supplies information the browser can use to make a connection. The address returned may depend on which records are available and how the service is configured. One name can have multiple addresses, and an address can host more than one website, so the relationship is not always one name to one machine.
The path from your device to an answer
A lookup usually starts with software on your device called a stub resolver. It may first find an answer in a local cache. If not, it asks a recursive resolver, often provided by your network or configured separately. The recursive resolver does the work of finding an answer and can cache it for later requests.
If the recursive resolver has no suitable cached answer, it follows a chain of DNS referrals. A root server points it toward the servers for the relevant top-level domain, such as .com. A top-level-domain server then points it toward the authoritative servers for example.com. An authoritative server holds the domain’s DNS records and can answer a question about www.example.com.
The resolver returns the result to your device, which can pass it to the browser. This description shows the logical path, not necessarily a fresh trip to every server for every page load. Caches at several points can shorten the process considerably.
Which DNS records provide an address?
DNS answers come in record types. An A record contains an IPv4 address, while an AAAA record contains an IPv6 address. A browser or operating system may request one or both types, depending on its configuration and network support. If a service publishes several addresses, the answer may contain more than one; the client then decides which address to try.
A CNAME record takes a different role: it says that one name is an alias for another name. For example, a hostname might point to a service provider’s hostname, whose A or AAAA records provide the eventual addresses. This adds another name to resolve; the CNAME itself is not an IP address. Other record types serve other purposes, such as MX records for directing email, and should not be mistaken for website addresses.
As an illustration, a lookup for www.example.com could return the documentation address 192.0.2.10 in an A record. That address is only an example, not a claim about where the site is hosted.
Why caching helps—and why changes take time
DNS records typically include a time to live, or TTL. This tells a resolver how long it may keep an answer in its cache before checking again. Caching reduces repeated queries and can make lookups faster. It also means that changing a record at an authoritative server does not instantly replace copies already held by resolvers.
Suppose a team changes a website’s A record to point to a new server. Some users may receive the new address while others still receive a cached answer until its TTL expires. An application or operating system may also retain DNS information locally. A missing-name response can be cached too, so repeatedly retrying a newly created hostname may not immediately produce a different result.
For small teams planning a move, the practical lesson is to check the intended records, account for existing cache lifetimes, and keep the old destination available during a transition when feasible. Lowering a TTL shortly before a change may not affect answers that were cached under the previous TTL.
What DNS does not guarantee
Receiving an IP address does not prove that a website is available. The server could be unreachable, or the web service could be misconfigured. If a lookup fails, the cause might instead be a misspelled name, a missing record, an unavailable resolver, or an issue with the domain’s authoritative servers. Separating “Did I get an address?” from “Can I connect to the service?” is a useful first troubleshooting step.
Traditional DNS queries are not necessarily encrypted. Encrypted DNS options can protect queries between a device and its resolver, while DNSSEC, where deployed and validated, helps check the authenticity of DNS answers. Neither feature by itself makes the destination website private or trustworthy. DNS is one part of the journey: it helps your device find an address, and other protocols handle the connection and the page that follows.
