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In this lecture, you are going to learn what DNS is and how it is used by everyone from major IT companies down to everyday home use all around the world.
DNS allows us to search the internet using names that we are familiar with.
For example: Have you ever used Google to search for the best prices on merchandise that you wanted to purchase? Your browser may answer your request by displaying ten stores that list current prices.
How does your computer's browser know how to do this?
What does DNS have to do with this?
The internet is made up of computers that are located strategically all over the world.
Computers communicate with each other using IP addresses. But we humans communicate using words. From your browser, if you type in www.google.com. You get google.com.
This is a lot easier than typing the IP address for google.com which is 172.217.8.14 now imagine if you had to type in the IP address for every website that you visited. Well, because of DNS you don’t have to.
DNS translates hostnames like google.com into IP addresses.
For example: If you type www.google.com and the IP address for google.com is in your local memory you will get the google icon and the google search box.
If the IP address is not in your local memory,
Your computer will go out to the internet where it will query a group of DNS servers.
If the first server does not have google.com in its local memory it passes that request on to the next server, if that server does not have google.com it passes that request down the line until it finds a match.
The hostname google.com has been found in DNS3’s local memory. DNS3 passes the IP address and the domain name down the line to the requesting DNS server in this case DNS1 until it reaches your computer. Each time a requesting DNS server finds a domain name the IP address is stored in the server’s local memory so the next time there is a request for google.com the DNS server will be able to respond more quickly.
Once your computer receives the IP address of google, your browser will know how to successfully connect to google.com.
- DNS allows us to search the internet using names we are familiar with.
- DNS converts domain names to IP addresses.
- So, the next time you type amazon.com or google.com into your computer's browser, you can say, this is no mystery because you now know and understand HOW DNS WORKS!
Thanks for watching, and we will see you at the next lecture.
