How Web Browsers work?

So what happens when you type URL and then hit enter. If we visit this URL:

Our system starts interacting with other system known as Server, its location is unknown or maybe thousand or miles away from us. And in millisecond seconds our system asks that server for a website, and that server starts to talk back to our computer in a language called HTTP.

Hypertext Transfer Protocol is an application protocol for distributed, collaborative, hypermedia information systems that allows users to communicate data on the World Wide Web.

The above image shows the conversation between a computer and a web server on the Internet, it's mainly made up of something called GET requests. So if you are sending a GET request to Server, and the Server sends the HTML code of the Homepage in response.

Hypertext Markup Language(HTML), a standardized system for tagging text files to achieve font, colour, graphic, and hyperlink effects on World Wide Web pages.

The text of the web page is included directly in the HTML, but other parts like Images or Videos are separated files with their own URLs that need to be requested. The browser sends separate HTTP requests for each of these and displays them as they arrive. Sometimes you send information like when you fill out a form or type a search query, were send in Plain text to the Web Server using an HTTP POST request.

Consider if you are submitting your login credentials in the Login form, then data is sent to the server in a POST request, and the server sends back the successful HTML page, along with this a little bit of invisible Cookie is stored. So the next time if you refresh the page, the browser automatically attaches the Cookie with the request and the server knows who is accessing the data.

HTTP cookies, or internet cookies, are built specifically for Internet web browsers to track, personalize, and save information about each user’s session.

Internet is an Open network and all the connections are shared and information is sent in Plain text. Hackers can snoop on the Information that is shared on the internet. We can prevent this by communicating on a secure channel. To make a secure channel, we need to use SSL(Secure Socket Layer) and its successor TLS(Transport Layer Security). SSL and TLS is a layer of security wrapped around communication to protect them from snooping and tampering. To check if the channel is secure or not, you can see the Lock icon or URL should start with HTTPS. To engage in a secure connection, it first provides a Digital Certificate.

A Digital Certificate is an electronic “password” that allows a person, organizaion to exchange data securely over the Internet using the public key infrastructure (PKI). Digital Certificate is also known as a public key certificate or identity certificate.

Developer with 3 yrs of industrial experience in developing scalable web applications.