title: What is the point of uWSGI?
body: <p>I'm looking at the <a href="https://en.wikipedia.org/wiki/Web_Server_Gateway_Interface" rel="noreferrer">WSGI specification</a> and I'm trying to figure out how servers like <a href="https://uwsgi-docs.readthedocs.io/en/latest" rel="noreferrer">uWSGI</a> fit into the picture. I understand the point of the WSGI spec is to separate web servers like nginx from web applications like something you'd write using <a href="http://flask.pocoo.org" rel="noreferrer">Flask</a>. What I don't understand is what uWSGI is for. Why can't nginx directly call my Flask application? Can't flask speak WSGI directly to it? Why does uWSGI need to get in between them?</p>
  
  <p>There are two sides in the WSGI spec: the server and the web app. Which side is uWSGI on?</p>