Firstly covering the simpler of the two options, the ASGI/WSGI web server that goes between your Python code in the web framework and the users who have a web browser:

Gunicorn is the most popular WSGI server
Uvicorn is an ASGI server. It is both a standalone server as well as a plugin for Gunicorn
Hypercorn is an alternative that supports both WSGI and ASGI