It’s a 2 in 2 out interface.
If the headphone output and the line out where separate it would be a 2 in 4 out interface.
You can set the output to be either output 1 (L) and or 2 (R) (mono) or 1 (L)/2 (R) Stereo that’s the choices.
Just plug in your speakers and or headphones and use the separate volume controls on the front of the interface.