DNS stands for Domain Name System and it acts like a virtual phone operator for the internet and local networks. When you type in www.askTheAdmin.com or \\YourServerName both of these requests hit up a DNS server to ask it a simple question.
Where is this website or computer located. The DNS server returns a IP address (just like a physical street address) and then your browser can find it.
From what I found online:
On the Internet, the Domain Name System (DNS) associates various sorts of information with so-called domain names; most importantly, it serves as the “phone book” for the Internet by translating human-readable computer hostnames, e.g. en.wikipedia.org, into the IP addresses, e.g. 22.214.171.124, that networking equipment needs for delivering information. It also stores other information such as the list of mail exchange servers that accept email for a given domain. In providing a worldwide keyword-based redirection service, the Domain Name System is an essential component of contemporary Internet use.
This is only the basics and you’ll find really good DNS info here
This is what happens when you type www.domainname.com into your computer’s web browser.
1. Your web browser asks the resolving DNS server what the address of www.domainname.com is. Your computer already knows where the local ISP resolving DNS server is through its network configuration.
2. The Resolving DNS server does not know the address. So it asks a root server the same question. The 13 root servers have globally well-known IP addresses, and are run by a US-based company called ICANN
3. The root server replies that it does not know, but it gives the address of the server which knows about .com domains.
4. The resolving DNS server asks the .com server what the address of www.domainname.com is.
5. The .com server replies that it does not know, but it gives the address of the server which knows about .domainname.com domain. This server is can be a managed server and many companies pay an annual fee (via a domain registar) to maintain this referral for their domain.
6. The resolving DNS server asks the .domainname.com server what the address of www.domainname.com is.
7. The server answers the query with the IP address of www.domainname.com, and marks the response as “authoratitve”. This is an assertion that the answer is correct and complete. It also adds to its reply that “this data is valid for 24 hours”, so that anyone who is asking can confidently re-use the information for that time without having to issue another query.
8. The resolving DNS server finally has its answer, and can reply back to the web browser with the IP address. Crucially it marks its answer as “non-authoratitive”, so that the web browser knows it has the information indirectly
Your fellow ITKE member Jenny Dempsey has an ITKE blog about domains and DNS. You may wish to visit her blog for more info about DNS, it’s called Domain Highway