How many concurrent requests does a single Flask process receive?
Flask will process one request per thread at the same time. If you have 2 processes with 4 threads each, that's 8 concurrent requests. 
Flask doesn't spawn or manage threads or processes. That's the responsability of the WSGI gateway (eg. gunicorn).
I'm building an app with Flask, but I don't know much about WSGI and it's HTTP base, Werkzeug. When I start serving a Flask application with gunicorn and 4 worker processes, does this mean that I can handle 4 concurrent requests?
I do mean concurrent requests, and not requests per second or anything else.