What is a DNS? - Definition & Explanation

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: What is an Internet Service Provider (ISP)? - Definition & Examples

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
 Replay
Your next lesson will play in 10 seconds
  • 0:04 What is DNS?
  • 2:01 How Does DNS Work?
  • 6:14 Lesson Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Timeline
Autoplay
Autoplay
Speed

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Lyna Griffin

Lyna has tutored undergraduate Information Management Systems and Database Development. She has a Bachelor's degree in Electrical Engineering and a Masters degree in Information Technology.

In this lesson, we will learn what DNS means, how it works and its functions in the world of the internet. We will see how it helps us navigate the complicated web of domains and IP addresses we are constantly requesting through our web browser.

What Is DNS?

A drunk named John hops into an Uber and says he wants to go to a particular late night club. The driver checks his GPS (directory) and looks through his list of saved destinations (cache) but can't find a destination (IP address) with that name (host name). He has never been to the place that John requested before and John is too drunk to give him the address! So, he calls one of his pals, who works in the downtown area (domain server). His pal checks his own GPS (cache) and finds the address to the club since he has taken clients there in the past and saved the address (cached) on his own GPS. He then sends the address back to John's cab driver and John is safely taken to his next club stop!

DNS stands for Domain Name System. A domain is a unique string (Gingernameclub.com) associated with an IP address. An IP address is a string of numbers used to identify a computer or resource on a network or internet. The Domain Name System (DNS) is a network of directories on the internet used to resolve host names (e.g., www.gingernameclub.com) into machine-readable IP addresses (e.g., 192.168.106.81).

Every computer, node, device or resource on the internet has a unique name and unique IP address. There are millions of such devices or resources. Computers communicate on the internet using the machine-readable IP addresses. Imagine if we needed to remember the IP addresses of all the pages we needed to visit or the resources we needed to access. Browsing the internet would be anything but fun.

Well, the DNS is what makes our lives so easy. It makes navigating this complex network of IP addresses user-friendly. It is the internet's address book/directory. It is the footman of our internet requests! The World Wide Web depends on the DNS to function as we know it today. Yes! DNS is that important!

How Does DNS Work?

With the millions of nodes and resources on the internet, their DNS information is not all kept in one place. The databases of DNS information are distributed worldwide.

It all starts with you, so let's go through these steps!

User Requests Information

You are at your computer connected to the internet and type the URL to the club John requested, www.gingernameclub.com, into your browser. You are actually requesting your browser to get you the web page of the Gingername Club. Your browser cannot work with names but with IP addresses. You are oblivious to the associated IP address. Your computer then checks its local DNS (John's Uber driver checks his personal GPS) to see whether it has cached information on this page before. Nope, your browser has never visited this page before. Therefore, your computer performs a DNS query (or when the Uber driver calls his pal).

A DNS query is the process by which a computer or device on a network makes an inquiry to other devices to get the IP address for a DNS name. In this case, we need the IP address of Gingernameclub.com.

Request Information from Recursive DNS Servers

If your computer fails to find the information in its local cache (saved query answers) it sends a DNS query to the servers hosted by your ISP (Internet Service Provider) through which you access the internet. These servers, known as recursive servers, may have the information cached. Recursive servers are servers which having their own cache, constantly refer back to themselves. If the recursive servers have the answer (IP address) then the information is sent back to your computer and the web page is displayed. IP address search is over.

To unlock this lesson you must be a Study.com Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use Study.com

Become a Study.com member and start learning now.
Become a Member  Back
What teachers are saying about Study.com
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account
Support