I am familiar with server technologies like ExpressJS and Flask. On the other hand I clearly understood the underlying concepts of CGI and Servlet. Flask/Django further extends CGI to WSGI and uses it. And, Servlet is so widely used in Java frameworks. Now, what is underneath ExpressJS/NodeJS ? I am completely blind and I don't even know if this is relevant.
Please correct if my question is idiotic. I am unable to inter relate these technologies.
