Sigmoid Function (and the Limits to Growth)

The sigmoid is a mathematical formulation that approximates an S when plotted. The unique feature of this function is that it is essentially two exponential functions. The first part of the function, growth occurs very quickly and is often called exponential growth. However, eventually some factor starts to limit the growth to a particular value such that no matter how much effort or time is given, it really never changes. As a data scientist, one often hears about exponential growth. However, questioning and understanding that the growth will eventually be limited is important such that one can model this limit to growth. How this is done is part of the art of data science.