etc
Are a WSGI server and HTTP server required to serve a Flask app?
https://stackoverflow.com/questions/38982807/are-a-wsgi-server-and-http-server-required-to-serve-a-flask-app
General
Why do I need Nginx and something like Gunicorn?
https://serverfault.com/questions/331256/why-do-i-need-nginx-and-something-like-gunicornWhat Is Gunicorn, and What Does It Do?
https://vsupalov.com/what-is-gunicorn/Green Unicorn (Gunicorn)
https://www.fullstackpython.com/green-unicorn-gunicorn.htmlGunicorn - Python WSGI HTTP Server for UNIX
https://gunicorn.org/What benefit is added by using Gunicorn + Nginx + Flask?
https://stackoverflow.com/questions/20766684/what-benefit-is-added-by-using-gunicorn-nginx-flaskWhat do Gunicorn and nginx do in a django deployment setup? - Quora
https://www.quora.com/What-do-Gunicorn-and-nginx-do-in-a-django-deployment-setupWhy is gunicorn so popular? - Quora
https://www.quora.com/Why-is-gunicorn-so-popularWhat is the use of Gunicorn? - Quora
https://www.quora.com/What-is-the-use-of-GunicornWhat are the differences between nginx and gunicorn? - Quora
https://www.quora.com/What-are-the-differences-between-nginx-and-gunicorn