The Composer (https://getcomposer.org/) is a dependency manager (packages) widely used in language PHP and provides many facilities, since it is responsible for checking, download to engage our project all the “libs” of third parties that we will need.
These “libs”, when downloaded by Composer, are grouped within a directory called “vendor”. In addition, a file called “autoload.php” is also created in this folder, responsible for “loading” all the classes we need to use. Basically, all I have to do is import “autoload.php” into a file of my project and I will have access to all classes of “libs” downloaded by Composer.