How data flows in Codeigniter

How data flows in Codeigniter-The Graphical representation of data flows in Codeigniter is given below:

The data flows in the following manner:

1. Firstly when the request is made, then it goes to the index.php  page.
2.  Index.php is the front controller file that is used to run all the files of Codeigniter. So, this is a base controller or front controller of CI.
3. After that the flow is routed to routing. It checks all HTTP (Hypertext Transfer Protocol) requests and sees if the cache version is present or not of this file request.
4. If the particular request version is present then it will show you the website on the browser. Otherwise, it will go to security.
5. After all the security checks, the request moves to the application controller.
6. This application controller, loads all the models, libraries, helpers, plugins, etc. After loading the data which is required for the website enters into the view.
7. Then view sends to catching and the website is viewed by user on index.php