In the Logic Pro Smart Controls pane, turn the knobs, click the switches, and move the other screen controls to see how they affect the sound of the patch.
Each screen control has a text label indicating what aspect of the sound it controls.
You can also change the layout for a Smart Control, save your own Smart Controls, map screen controls to channel strip and plug-in parameters, and assign controllers on your MIDI devices to screen controls. For more information about using Smart Controls, see Apple Books | PDF