curve fitting using min-max optimization

I have a 2D array and I am trying to fit a curve on the data.how can I find the best curve for the data in Matlab? I need to know how much this model is good. what is the difference between actual data and estimated curve? how can I find this? does Matlab curve fitting works based on mean square error to find the curve? how can I control this difference? is it possible to consider min-max error to find the best fit? my data is as following image. but I do not know how can I find the red curve.

Answer 1

[Stephan]

You might want to start reading and trying here: https://de.mathworks.com/help/curvefit/curvefitter-app.html