You type a name, but the network needs a number. Follow the lookup as a resolver walks the hierarchy and brings back the IP address for the site you asked for.
Domain name resolution is the process that turns a name people can remember, such as example.com, into the numeric IP address that computers actually use. Names are for us; addresses are for the machines. DNS is the system that keeps the two in step.
Because no single server holds the whole directory, the answer is found by asking a small chain of servers, each of which knows only its own part of the map. That chain is what this diagram follows.
The DNS database is deliberately spread across levels so it can scale. A root server does not know every website; it only knows which server handles a top-level domain such as .com. That server, in turn, only knows which server is responsible for a particular domain. Only the authoritative server holds the actual record.
Each answer narrows the search until one server can reply with the final address, which then travels back the way it came.
Everything starts when you enter an address. Before any page can load, the browser needs to convert the name into an IP address, so it hands the question to a recursive resolver.
Rather than making your device walk the hierarchy, the resolver does the chasing. It checks its own cache first, and if the answer is missing it starts querying other servers on your behalf.
The resolver's first stop is a root name server. The root does not know the website, but it knows which server is responsible for the top-level domain â the .com part of the name â and sends the resolver there.
The .com server does not hold the site's record either. It points to the authoritative name server for that specific domain, the only server that owns the real entries.
The authoritative server looks up the name and answers with the matching IP address. This is the only server in the chain that is allowed to give a final, authoritative answer.
On the way back, the resolver stores the record for a while and hands the IP to the browser. Next time the same name is requested, the cached answer can be served immediately, skipping the whole chain.
DNS turns a human-friendly name such as example.com into the numeric IP address that computers use to find each other. Bookmarkable names stay readable while the network keeps working with addresses.
It is the server your device asks first, usually provided by your ISP or a public service. Instead of making you walk the hierarchy, it does the chasing for you and hands back one final answer.
The DNS database is split across levels. A root server knows where the top-level domain servers are, a TLD server knows a domain's authoritative server, and only the authoritative server holds the actual record.
Each one answers a narrower question. Root points to the top-level domain, the TLD points to the domain's own server, and the authoritative server is the final source that returns the address for the specific name.
Once a resolver has a record, it stores it for a while. A repeat lookup for the same name can be answered straight from that cache instead of walking the whole hierarchy again.
No. Browsers, operating systems and resolvers all keep short-lived caches. On a warm cache the full chain is skipped, which is why a second visit to a site often feels instant.