Contributing developers—update, reinstall Magento | Magento 2 Developer Documentation

The following topics apply to you only if you used git clone to install the Magento Open Source GitHub repository. This usually means you contribute code to the Magento Open Source codebase.

If you clone the Magento 2 GitHub repository, you cannot use the Magento software in a production environment. You cannot have a live store that accepts orders and so on.

To update the Magento software, use git pull origin and composer update, then update the Magento database
To change versions from develop to a release version like 2.0.4, you must uninstall the Magento software and install the released version.
To add, remove, or update components, modify composer.json and run composer update and update the Magento database
To reinstall the Magento software, modify the product version in composer.json, run composer update, then reinstall the Magento software

If you are not a contributing developer, you perform upgrades and upgrades as discussed in Updating the Magento application and components.