When we type https://www.google.com we are requesting a web page, file, or application in a server, and within a blink of an eye we will be served with our request but there are lots of processes it undergoes before serving us our request.
Before explaining let me list the infrastructure or technical stage that we will cover:
– DNS server
– Web server
– Application Server
The first step is a domain lookup. Normally, every device on the Internet has a unique number used to identify it and connect it with other devices. The number is called the IP address and it’s looking like this 182.167.03.1
Just take it as a phone book, everyone has a phone number but we use their name to save the numbers because, unlike computers, it’s difficult for us as human beings to memorize digits, therefore it’s the s same thing with the domain.
The domain name is just like a cover of an IP address of a website so the first step is to look up the IP address assigned to that domain.
There are 4 steps that the DNS lookup undergoes which we will look into later but I will briefly try to explain it.
First of all, it will check on your browser caches maybe you have visited it recently if it’s there it will return it otherwise, it will proceed and check your OS if it couldn’t find it there too, it will redirect it to DNS server.
You can take the process as you go to a bookshop and ask for a particular book and the bookkeeper look around if it’s among the recent books checked if it’s not among he/she looks around if he/she can sees if he/she couldn’t see it then he/she brought out a book like a dictionary with all the list of books they have in the store.
So the DNS root will be checked if it’s there it will return it otherwise it will return an error.
The second step is Transfer Protocols
Since we know where to find our web page now how do we pull it? It’s by the help of HTTP/HTTPS which stand for Hypertext Transfer Protocol it’s a design system that allows communication between the client and the server.
(the client here refers to you, the web browser, and the device you are using to request)
As the connections are established let’s start transferring but before them, there’s a need to secure the traffic.
How do we do that?
Using HTTPS is also the same as HTTP the “S” added at the end stands for security. Since the HTTP protocol is the request and response protocol it’s needs security so comes the SSL certificate which stands for Secure Socket layer.
SSL is a protocol for servers that makes sure the connections between servers are secured
Firewall: a software or hardware design to secure the traffic from unauthorized access to your web and applications server and database.
Just take it as a wall surrounding your house with security at the gate giving access to only certain people in your house.
A web server is a server that server statics content like HTML, CSS, and image
The applications server is a server that serves dynamics content like PHP, Js
The database is a collection of data and the database server is a server program that interacts.