How a Website Name Finds Its Server
A browser can show a person-friendly address such as `example.com`, but the computers exchanging data need an IP address—a numerical destination. The Domain Name System, or DNS, supplies the connection between the name and that number. It does not carry the webpage itself; it helps the browser learn where to ask for it.
A Lookup That Can Follow Several Steps
When a device needs an address, it usually asks a DNS resolver, a service provided by a network or another DNS provider. If the resolver has a usable saved answer, it returns it immediately. Otherwise, it follows the DNS hierarchy: it can ask a root server where to find the relevant top-level domain, such as `.com`, then ask that domain’s servers which name servers handle the specific website. Those servers provide the requested record, including the IP address.
The resolver passes the result back to the device, which can then contact the server. This separation lets website names remain easy to remember while network destinations are represented in a form computers can route to.
Why Answers Are Saved
DNS records come with a time-to-live, or TTL: a period telling resolvers how long they may reuse an answer before checking again. Caching—the practice of keeping a copy for later—reduces repeated queries, saves work for DNS servers, and can make visits quicker. A device, router, or resolver may each keep its own cache.
The tradeoff is that a changed address may not reach every visitor at once. A resolver that still has an unexpired old answer can keep using it until the TTL runs out. DNS makes the internet’s naming system efficient by remembering answers, but that memory is temporary.
