Flask is a lightweight and extensible web microframework for building web applications using Python. It was developed by Armin Ronacher and is designed to be simple and easy to use, making it suitable for both beginners and experienced developers. One of its key features is the use of decorators to define routes, which map URLs to Python functions, resulting in clean and readable code ⁴⁵.

Flask does not come with built-in components like database management or form validation, which allows developers to choose their preferred libraries and tools. This flexibility is one of the reasons why Flask is often considered more Pythonic than other frameworks, such as Django, which has a more monolithic structure ³⁴.

Additionally, Flask includes a built-in development server and debugger, which enhances the development process by providing detailed error messages and automatic server reloading when code changes are made ⁵.

If you’re interested in starting a project with Flask, there are various templates and boilerplates available to help you set up your application quickly ¹.