Default:
Enables you to deploy the Magento application on a single server without changing any settings. However, default mode is not optimized for production.
To deploy the Magento application on more than one server or to optimize it for production, change to one of the other modes.
Symlinks to static view files are published to the pub/static directory
Exceptions are not displayed to the user; instead, exceptions are written to log files.
Hides custom X-Magento-* HTTP request and response headers
Developer:
Intended for development only, this mode:
Symlinks to static view files are published to the pub/static directory
Provides verbose logging
Enables automatic code compilation
Enables enhanced debugging
Shows custom X-Magento-* HTTP request and response headers
Results in the slowest performance (because of the preceding)
Magento Commerce (Cloud) supports production mode only.
Production:
Intended for deployment on a production system, this mode:
Does not show exceptions to the user (exceptions are written to logs only).
Serves static view files from cache only.
Prevents automatic code file compilation. New or updated files are not written to the file system.
Does not allow you to enable or disable cache types in Magento Admin.
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