Regression analysis determines the relationship between one dependent variable and a set of independent variables. This sounds a bit complicated, so let’s look at an example.Imagine that you run your own restaurant. You have a waiter who receives tips. The size of those tips usually correlates with the total sum for the meal. The bigger they are, the more expensive the meal was.You have a list of order numbers and tips received. If you tried to reconstruct how large each meal was with just the tip data (a dependent variable), this would be an example of a simple linear regression analysis.(This example was borrowed from the magnificent video by Brandon Foltz.)A similar case would be trying to predict how much the apartment will cost based just on its size. While this estimation is not perfect, a larger apartment will usually cost more than a smaller one.To be honest, simple linear regression is not the only type of regression in machine learning and not even the most practical one. However, it is the easiest to understand.