Usage of Composer
Composer - a dependency manager, or rather, a package manager for php.
Official website: https://getcomposer.org/
Allows you to keep track of components used in a php application, install them, update them, etc.
Doctrine. Structure. Entity
Right after starting to work with Doctrine I acquired some prejudices. I have since eradicated them, but maybe someone still has them, maybe this note will help someone =)