TargetSurface..... Does anyone know the function of this advanced Command Flow?

[version3d]

TargetSurface…What is this in command flow?
Someone can answer me?

[pascal (Pascal Golay)]

Hello - the F1 key will bring you to the Help file -
https://docs.mcneel.com/rhino/7/help/en-us/index.htm#commands/flow.htm?Highlight=flow
-Pascal

[version3d]

Thank you very much. for helping…