DNS: The Internet's Phone Book

DNS stands for Domain Name System (or specifically Domain Name Server). It helps computers and devices find websites on the internet. Imagine the internet is like a big city, and each website is a house, that is located within a neighbourhood in that city. To visit a house, you need to know its address. In the same way, to visit a website, your computer needs its address too. DNS works like a phonebook, helping your computer find the address of the server (the neighbourhood) that hosts the website (house) you want to visit.

How DNS Works

Components

There are 3 main components contained within a domain.

1. The Domain Name (the actual name of the domain and/or subdomain you are trying to access)
2. The name server that holds the DNS records
3. The actual DNS records themselves

The Digital Pathway

1. In your browser, you specify a website name: When you want to visit a website, you type its name (like www.example.com) into your web browser.
2. Asking the DOMAIN for help: Your computer doesn't understand the website's name specifically, so it asks the domain where there DNS records are stored (This is the Name Server specified within the Domain itself)
3. Your browser is directed to check the Name Server for the directions to website's actual server location. It looks up the records for the "www" sub-domain.  (It could also be asking for an FTP site, Email server, file server, etc...)
4. DNS finds the address: The DNS stored looks in its phonebook stored at the Name Server and finds the specific server (A computer that has been assigned a specific Internet Protocol or IP address) that matches the website's name.
5. Your computer visits the web server: Once your computer has the IP address, it can visit the server that the website lives on.  From there traffic is routed to your specific website's file structure.

Example

Imagine you want to visit www.example.com.

1. You type www.example.com into your web browser.
2. Your computer asks the domain, "Where are the DNS records for this domain?"
3. After being routed to the Name Server, the computer then asks the DNS, "What's the address for www.example.com?"
4. The DNS finds the IP address (like 123.45.678.9) for the subdomain "www" located on the domain "example.com".
5. Your computer grabs the IP address and routes there to visit the website.

So, DNS helps your computer find websites on the internet by turning website names into addresses that your computer can understand. DNS works for ALL internet traffic.  Not just websites.  But FTP (File Transfer), Video, Audio, Email, and any other service that occurs over the internet.

DNS Servers

There are thousands of DNS servers around the world. Your computer or internet provider utilizes a local or specified DNS server to provide the specific location of internet services.  All the world's DNS servers are synchronized to provide the same data so that a website request anywhere in the world will point to the user's web browser to the same place.  When a change is made to a website or web server, it usually takes between 12 to 24 hours for this change to propagate around the world.  In that time, traffic can be routed to the old OR the new server, depending on how well the change has been propagated.

Simple?  

Ok... Maybe not that simple.  But it works quite well.  If you have questions with your domain, or would like domain services... contact us!