What is DNS? | How a DNS Server (Domain Name System) works | DNS Explained

when was the last time you remembered your friend's phone number never right well who remembers phone numbers that's what contacts in your phone books are for you save the number in the phone book and then you never have to worry about that number again well similarly dns is a giant contact list of the internet that maps our domain names with the ip addresses now to understand how dns works let's consider what happens when we request a website on the internet now let's say you type www cloud in your web browser now your query actually travels the internet and reaches your internet service provider to the dns resolver this resolver then queries the dns root server with this exact domain in this case the cloudgirl.dev with the www and then the root server basically says that i don't know what the ip address for that is but i do know that you have to go to dot dev top level domain name server which might know what the address is so then the dns resolver goes to the dev tld name server which says it takes this piece right here now and it says i don't really know the ip address for the whole thing right but i do know the that you can go to the cloudgirl.dev you can go to the cloudgirl.dev domain and that server would know the ip address for www so then the dns resolver goes to the authoritative name server for the cloudgirl.dev and it returns back the ip address for it which could be anything let's say it's 192.0.2.40 maybe and then once i have that ip address the dns resolver then sends it back to through the internet obviously to your computer and then from there it sends that request to the web server which is sitting at 192.0.2.40 and then that web server responds back with the actual web page which gets displayed to the user now what we just saw here is when the resolver makes multiple queries to different name servers and then gets the ip address and then sends it back to the user now this doesn't always happen you know why how many times does the phone number for your friend changes not very often right it's kind of the case with the dns too so it's safe to cache the dns results at multiple locations in most cases browsers cache the dns results or the queries so in this case if the same user if i go to www.dolcloudgirl.dev again my browser knows or it has cached the dns record for that for that address for that host similarly if my browser didn't have it somebody else queried for the website right so the isp which was my internet service provider also caches the dns record so if it didn't find it in the browser cache it's likely be found in the internet service providers cache and then from there it would just return the ip address right from here so it wouldn't have to go through this entire recursive query process if it just takes it from the cache which is what happens in most cases because the dns records don't often change hopefully this helped you understand dns and how it works if you would like to see more fundamental concepts like this i would like to know that from you so please put that in the comments below and don't forget to like and subscribe for more cloud content thank you

Channel: The Cloud Girl

Views: 1,673

Rating: 4.9633026 out of 5

Keywords: priyanka vergadia, pvergadia, osi model, osi 7 layers, osi, Open System Interconnection Model, networking, cloud networking, cloud computing, thecloudgirl.dev, the cloud girl, cloud girl, DNS, domain name system, domain name server, name server, domain name explained, dns explained, what is dns

Id: g6R9gRWIIK8

Length: 4min 13sec (253 seconds)

Published: Tue May 18 2021