Composer
In plain terms
The dependency manager for PHP.
Going deeper
Composer manages PHP libraries and autoloading via a composer.json file, pulling packages from Packagist. It standardized modern PHP dependency management.
Under the hood
Handles transitive dependencies and PSR-4 autoloading; central to frameworks like Laravel and Symfony.
Examples
composer.json, Packagist, Laravel/Symfony, PHP autoloading, dependencies.
Think of it like...
Like a librarian fetching and organizing all the PHP libraries your project needs.