Problem with automatic search path based on class name in PHP framework

I am new to PHP. I looked at some frameworks and found that in a class, when new a new class, there is no include or require in this file. The instantiation can be completed according to the specific class name required. After looking at the code, I understand that a spl_autoload_register technology is used.
The following is a simple diagram

Component, controller, and interface are part of the many folders of the framework. In the logical process, there is no direct include or require of the component_XX class, which can be instantiated, mainly through the above spl_autoload_register technology.
Give me a link about this technology and you will know
http://blog.csdn.net/panpan639944806/article/details/23192267

').addClass('pre-numbering').hide(); $(this).addClass('has-numbering').parent().append($numbering); for (i = 1; i ').text(i)); }; $numbering.fadeIn(1700); }); });

The above has introduced the problem of automatically searching paths based on class names in the PHP framework, including aspects of it. I hope it will be helpful to friends who are interested in PHP tutorials.