Linear/Non Linear?

[Visavis <Visavis@xxxxxxxxxxxxx>]

May I ask what is the difference of linear & non linear trend following system?  Is it systematic & discretionary? -
v^v^v^v^v^v^v^v^v^v^v^v^v^v^v Visavis v^v^v^v^v^v^v^v^v^v^v^v^v^v^v