What is the difference between "Port" and "Upload Port"?

If there isn't any, this does not make sense:


The GUI gives the correct assessment: ESP32 Dev Module at /dev/ttyUSB0. But the uploader (?) is "Waiting for upload port..." and is waiting for 10 sec before it uses the default configuration "as default"?

Why 10 sec waiting for what and why the fallback for what is set?