ELI5: Explain Like I'm 5

Line fitting

Line fitting is a way to find the best line between data points. For example, if you have a list of numbers that were measured, it could be helpful to draw a line that best connects them. This is what line fitting does - it finds the best line it can so that it looks like all the data points are following the same path. It's like connecting the dots, except it makes sure the line is as straight as it can be.