Let’s just say that Tiny Tim wants to take a look at a certain web page, jobprospects.cratchet.scrooge.com.

Tiny Tim writes in the domain name on his web browser and hits return. Tiny Tim’s web browser turns Tim’s statement, "jobprospects.cratchet.scrooge.com" into a question "Where is jobprospects.cratchet.scrooge.com?" and directs the question to Tim’s TCP/IP (Transfer Control Protocol/Internet Protocol) stack in Tim’s computer.

Tim’s computer has a setting, telling it where to go to get answers to questions like that, usually the DNS resolver at his ISP. Tim’s computer asks the resolver, "Where is jobprospects.cratchet.scrooge.com.?"

The resolver at Tim’s ISP may know the answer to this question. Most resolvers keep a record (or cache) of domain names. If Tim had just recently asked about jobprospects.cratchet.scrooge.com, it still might remember. But let’s assume it doesn’t.

If the resolver at Tim’s ISP doesn’t have an answer, it knows to go to the root servers. There are currently 13 root servers situated around the world. The root servers know how to find the top level domain servers, like the com, edu, and uk. Some of these root servers even know where to find second level domain names like scrooge.com. The resolver asks one or more root servers "where is jobprospects.cratchet.scrooge.com?" None of the root servers would know the answer to that.

"Ask a com server. Here are a couple of addresses for com servers." is the probable answer.

So the resolver will then use the addresses it has been given to ask one or more com servers: "Where is jobprospects.cratchet.scrooge.com?"

The com server won’t know the answer either. However, the com server knows where all the servers for the com domains are, so it will reply "I have at least two different addresses for scrooge.com’s name servers, go ask them."

The resolver will then contact the name servers at scrooge.com. The name servers at scrooge.com just might have the answer. If there has been an outbound request for jobprospects.cratchet.scrooge.com, if someone at scrooge.com has asked that question, the answer may be cached. If not, the resolver will be directed to the two or more name servers that deal with cratchet.scrooge.com.

If jobprospects.cratchet.scrooge.com is a record in cratchet.scrooge.com, then cratchet.scrooge.com can provide the address. If not then it will direct the resolver to the addresses for the name servers for jobprospects.cratchet.scrooge.com, which will be able to answer the question. In either case, the resolver now has its answer. Only now does the resolver respond to Tim’s TCP/IP stack request. Tim’s browser then seeks out the appropriate Internet address.