uWSGI vs WSGI

 uWSGI is open-source software that implements many different APIs to run Python, Ruby, Perl, and even CGI apps.

WSGI is the API between Web Server and Python Web applications. uWSGI originally only supported WSGI, which may be the reason why it has such a confusing name.

uWSGI uses its own protocol, uwsgi (another bad naming example), to communicate with a general web server like Nginx.

The below picture says everything about it.