what happens when we enter url in browser and hit enter

All You need to know about surfing the internet when you hit a website.

All of us surf the internet almost daily.But what happens while browsing and whats the back end process. Hope my explanation will guide you.

First of all when we want to surf the internet we open a web browser and we locate the address bar or the URL bar. URL is nothing but Uniform resource locator. We enter the website address in the URL space or what we call the
address bar and we hit enter.

Actually what happens is every website has a web server and when we connect it we actually connect to the web server, each web server has an IP address. For example for www.google.com the IP address is 209.85.175.99 .so instead of entering www.google.com you can also enter the IP address and it will direct you to the google homepage.

But why do we use Domain names instead of IP address?
The answer for this question is so simple that we as humans we find it difficult the remember numbers that's the IP address.

Let us consider a real life example, as of today if we consider that you know 100 websites by heart and you use them regularly , if at all you had to remember the IP address for those 100 websites instead of the Domain names do you think that you will remember ? Certainly not. so only for the advantage of the humans this IP to Domain name Conversion has been implemented.

Now let us study how does this work. Now the scenario is you want to connect to a web server of a particular IP address and you don't know the actual IP address. You know only the DOMAIN name.

There are some servers known as DNS, these are Domain Name Server. Each web server has its own Domain Name server. It is the work of this server to Convert the Name into the IP address. Let us consider you and me as the client for the web server. The Scenario now is that the client wants to connect to the server but the client don't know the IP address of the server it just know the Domain name so can the client connect to the Domain Name server of the web server and get the IP and then connect itself to their server?

No the Client without knowing the IP address of the server it has to collect the IP and then with the Ip only it can establish connection.

What does the client do in order to know the IP?
There are 10 ROOT DOMAIN NAME SERVERS IN THE WORLD,when the client enters the domain the Local Domain Name Server of the client is checked whether it has any Cache and in that the IP is available for the requested domain. The Local Domain name server will contain the IP address if an only if the Domain has been visited previously.
In this case the IP address is retrieved from the local Domain Name Server and the connection is established between the client and the requested web server.

Now what if the local Domain Name Server dosen't contain the Ip address of the requested Domain.In such a case the Local DoMain name server contacts the root Domain Name server. The root Domain name server just looks at the ending portion of the domain whether it is .com or .net or so , then it transfers the control to the DNS server of .COM .net or the specified extension. Then in this case let us consider client has requested for an .com website.

So now the control has been transferred to the .com Domain Name server. Now the .com Domain name server reads the sub domain or the domain itself if there is no sub domain and it points or transfers control to the Domain Name Server of the requested
web server.

Now the control has been transferred to the requested web server's Domain name server. This Server has the IP address of its web server and it gives it to
the client.

Now the Client has got the IP address of the requested web server and it connects to the website directly. Thus this is what happens when you enter a website in the browser and hit enter.

Story taken from Here with courtesy and thanks