Can somebody explain to me the difference between linear model and loess model in statistics? I need to explain this to non-math people.
A VERY non-technical answer
A simple linear model fits a straight line through a set of points. The line is the best possible straight line (at least, for one sensible definition of best)
A loess model fits a complicated curve through a set of points. In some ways, it can be thought of as a complicated moving average. It is the best possible curve (at least, for one sensible definition of best)
This may help explain what loess does and may help in an explanation of the difference.