Composer
Composer is a tool that handles dependency management in PHP. It is not a package manager like Yum and Apt on Linux systems are. Though it deals with libraries (packages), it does so on a per-project level. It does not install anything globally. Composer is a multiplatform tool. Therefore, it runs equally well on Windows, Linux, and OS X.
Installing Composer on a machine is as simple as running the installer in the project directory by using the following command:
curl -sS https://getcomposer.org/installer | php
More information about the installation of Composer can be found on its official website, which can be viewed by visiting https://getcomposer.org.
Composer is used to fetch Magento and the third-party components that it uses. As seen in the previous chapter, the following composer
command is what pulls everything into the specified directory:
composer create-project --repository-url=https://repo.magento.com/ magento/project-enterprise-edition <installation directory name...