Difference between Flask and IIS(Internet Information Service) or Apache

Question

When I run my service through flask, I can access that service from any other system. When I host my service on IIS or Apache even then I can access it from other system. May I know, can flask alone can be used to make my service public or I need to run my flask on IIS or Apache. I'm new to flask and IIS please help me with this.

Answer 1

Flask has a built-in WSGI server called Werkzeug
Technically you can use flask and access it's web app directly.
Production-wise it's better to use a Reverse proxy (like Nginx) , and a production WSGI server (like Gunicorn)