How browsers work

How browsers work

After entering a URL in a browser, a beautiful page is displayed in front of us. What happened in the middle? For a common user, you may not need to think about this problem. But as a front-end developer or a developer who wants to develop plug-ins, it is necessary to master the working principle of the browser!

Main browser Functions

Today we will discuss five mainstream browsers: IE, Firefox, Safari, Chrome, and Opera. The functions and purposes of the browser are the same, but there will be some differences in the parsing process. What are the main functions of the browser?

1. user Interface (this is not important)-including the address bar, the back/forward button, and the bookmarks directory, that is, what you see is not only used to display the main window of the page you requested.
2. browser engine-used for query andOperation Rendering Engine. Also used to operate the browserData Storage.
3. Rendering Engine-usedDisplayThe request content. For example, if the request content is html, it is responsible for parsing html and css and displaying the parsed results.
4. Network-used to complete network calls, such as http requests. It has platform-independent interfaces and can work on different platforms.
5. The UI backend is used to draw basic components such as a combination selection box and a dialog box. It has a common interface not specific to a platform and uses the user interface of the operating system at the underlying layer.
6. JS interpreter-used to explain the execution of JS Code.
7. Data Storage-a persistent layer. Browsers need to store cookie-like data on hard disks. HTML5 defines the web database technology, which is a lightweight and complete client storage technology.

 

Figure 1: main browser Components

Unlike most browsers, Chrome allocates rendering engine instances for each Tab. Each Tab is an independent process.

Reference page:

Tutorial _-HTML

 

Tutorial _-HTML-Introduction to HTML

 

Tutorial _-HTML Basics

 

Tutorial _-HTML elements

 

Tutorial _-HTML attributes

 

Tutorial _-HTML tutorial-HTML title

 

Tutorial _-HTML section

 

Tutorial _-HTML tutorial-HTML link

 

Tutorial _-HTML tutorial-HTML head http://www.piliyuan.com/HTML/22.html

 

_-HTML tutorial-html css http://www.piliyuan.com/HTML/23.html

 

Tutorial-HTML tutorial-HTML image http://www.piliyuan.com/HTML/24.html

 

_-HTML tutorial-HTML table introduction http://www.piliyuan.com/HTML/27.html

 

_-HTML tutorial-HTML list http://www.piliyuan.com/HTML/28.html