Magento 2.0.18 is the final 2.0.x release. After March 2018, Magento 2.0.x will no longer receive security patches, quality fixes, or documentation updates.
To maintain your site's performance, security, and PCI compliance, upgrade to the latest version of Magento.

Introduction to Composer

We use Composer to manage Magento components and their dependencies. Using Composer to get the Magento software metapackage provides the following advantages:

  • Reuse third-party libraries without bundling them with source code
  • Reduce extension conflicts and compatibility issues by using a component-based architecture with robust dependency management
  • Adhere to PHP-Framework Interoperability Group (FIG) standards
  • Repackage Magento Open Source with other components
  • Use the Magento software in a production environment

You must create a Composer project from our metapackage if you want to use the Magento Web Setup Wizard to upgrade the Magento software and third-party extensions.

The key to developing any Magento component is its composer.json, which specifies version and dependency information for a component, among other things. You can look at Magento 2 code, such as:

For more information

For more information about Composer, see the Composer documentation.