Yes, it counts.
nginx
is written in C and handles all what shall web server handle for your static files.
Apart from speed, you will also get lower load on your Python code.
Regarding caching - if you like, nginx
can serve for your app also as a cache, see NGINX doc. But if the request is to be processed by Flask, there is nothing nginx
would speed up apart of offloading your app by e.g. serving static files.
The extra effort for configuring nginx
for static files might not be necessary while developing an app, but for production use I would recommend it.