What is regression?
Regression is normally the first algorithm that people in machine learning work with. It allows us to make predictions from data by learning about the relationship between a given set of dependent and independent variables. It has its use in almost every field; anywhere that has an interest in drawing relationships between two or more things will find a use for regression.
Consider the case of house price estimation. There are many factors that can have an impact on the house price: the number of rooms, the floor area, the locality, the availability of amenities, the parking space, and so on. Regression analysis can help us in finding the mathematical relationship between these factors and the house price.
Let us imagine a simpler world where only the area of the house determines its price. Using regression we could determine the relationship between the area of the house (independent variable: these are the variables that do not depend upon any other variables...