What is and how a browser works and how to make us view the web pages

When you open yours browser Favorite and type a web address, have you ever wondered what happens “behind the scenes”? The process that allows you to view a web page is more complex than it seems and involves a global network of computers and protocols that work in sync. The browser, or the software that allows us to surf the internet, sends requests to the servers where the sites reside and receives the data in response which then transforms into visible pages. This exchange takes place through communication protocols such as Http And Httpswhile the DNS deals with translating the addresses we type in Royal IP addresses. Once the files are received from the server, the browser interprets and displays them, combining code HTML, CSS And Javascript To create the final aspect of the site. This apparently immediate process hides a series of fundamental technical passages that make our daily online experience possible. Let’s see them a little more closely, so as to understand How a browser works and how to make us view the web pages.

The two main protagonists: clients and servers

To understand the operation of a browser, you have to start from the two Main protagonists of web navigation: The client and the server. The client is the device from which you connect to the Internet, whether it is a computer, smartphone or tablet, has no importance. The server, on the other hand, is a remote computer that houses the sites and provides them on request. When you insert a URL in the addresses bar, the browser starts a whole series of operations to recover and view the page.

The first step is the Search for the IP address of the website through the DNS (Domain Name System), a sort of “column” that associates the addresses type, such as Geopop.itto the real numerical addresses of the servers. This is because computers do not directly include domain names, but work with unique numbers called IP addresses (for example, 192.0.2.172).

Once the correct server is identified, the browser sends a request Http (or Httpsif the site uses a safe connection) asking him to send a copy of the website to the client. To be clear, Http stands for Hypetext Transfer Protocol And it is the Protocol that allows communication between clients and servers. If the server approves the request, he replies with a status message, usually “200 ok”and starts Send the website files to small data packages.

These packages travel through the network using protocols such as TCP/IP (Transmission Control Protocol / Internet Protocol), who deal with ensuring that the data correctly arrive at the browser. Once received, The browser “recomposes” the packages and starts elaborating the files that make up the web page.

Why the technique just mentioned is necessary, also known as Package switch? The reasons are different: in case of loss or corruption of a data, it is easier to replace a single package instead of having to recover an entire block of data. Furthermore, the packages can be unplugged on different routes, increasing the transfer speed and allowing multiple users to download the same website simultaneously. If, on the other hand, each site was sent as a single mega block, only one user at a time could download it, making the whole experience online very slow and frustrating.

As a website is composed: the features

And speaking of the site that is “recomposed” by the browser, it is useful to understand at this point How is a website composed. Conceptually, we can divide the files that make it up into two macrocastreors: Code files And resource. Code files can be made with various languages:

  • HTML (Hypetext Markup Language): It is the most used Markup language for web documents, which allows you to define the structure of the page, indicating the position of elements such as texts, images and links.
  • CSS (Cascading Style Sheets): It is a language used to define the formatting of HTML documents, which therefore affects the graphic appearance of the web pages.
  • JavaScript: It is a programming language that allows you to add interactivity and dynamics advanced to the pages, such as animations or updates in real time.

As for the Resources fileson the other hand, by this term we mean the set of all the elements that make up a website, such as images, music, videos, pdfs, etc.
The browser follows a precise order to upload these files. Before Analyze the HTMLidentifying any references to external CSS and JavaScript files. Then Download and interpret the CSScreating a structure called Cssom (Cascading Style Sheets Object Model), which defines the visual style of the page. In the end, Performs the JavaScript codeallowing any animations, effects or interactions with the user.

While these processes take place, the browser builds a representation of the page in the form of Dom (Document Object Model), one Tree structure that maps all the elements of the page. Once this phase is completed, the browser rendering engine Combine the Dom with the CSSOM to generate the final display of the page, which can now be explored and used in all respects.

In addition to all this, modern browsers manage other important aspects of navigation, such as the storage of data in cookies (text files used by sites to remember preferences and user sessions) and the safety of connections through SSL/TLS certificatesessential to guarantee the privacy of the information exchanged online.

All these operations, of course, take place in the period of fractions of second! And this should make us appreciate even more the work of our browser which is, in all respects, much more than a simple window on the internet: it is a sophisticated processing tool that translates the raw data in visual and interactive experiences, making the Web accessible to everyone.