Flask – Environment

Flask is a micro web framework written in Python. An environment in Flask is a concept that allows the application to know where it's running and what configurations it should use. The environment can be set using the "FLASK_ENV" environment variable, which can take values such as "development", "testing", and "production". When the environment is set to "development", the application will run in debug mode, providing helpful error messages and a debugger. In "testing" mode, the application can be configured to run with a separate testing database. In "production" mode, the application should be run with a WSGI server, such as Gunicorn or uWSGI, to handle production-level traffic and load.