Flask is a Python web framework used for developing web applications, web services, web resources, and web APIs.

Flask has several key features, including a lightweight and modular design, a built-in development server, ability to handle HTTP requests and responses, support for URL routing, template rendering, and session management.

Some advantages of using Flask over other Python web frameworks include its simplicity and ease of use, its flexibility and modularity, and its support for rapid development and prototyping.

The key responsibilities of a Flask developer include developing and maintaining web applications using Flask, designing and implementing APIs and web services, working with databases to store and retrieve data, ensuring the security and performance of the application, and collaborating with other team members to develop and deploy web applications.

Flask and Django are both Python web frameworks, but they have some key differences. Flask is a microframework, meaning it is lightweight and does not have as many built-in features as Django.

Flask has a highly active and supportive community. There is an active forum, official documentation, and a wide range of extensions and packages contributed by the community. Flask also organizes regular conferences and meetups, providing opportunities for developers to connect and share their knowledge and experiences.