Hello everyone, In this article, I will try to explain what Linear Regression is by simply supporting it with my expressions and graphic images. I wish you pleasant reading.

First of all, I would like to briefly touch on what regression is; Expresses the relationship between two or more variables. For example, if we consider people's age and height as two variables, there are relationships between these two time-varying parameters at certain periods. The graph in figure 1 below visually supports the concept of regression — relationship of variables.

What Is Linear Regression? — **Figure 1**

Coming to the subject of linear regression, which is our main topic, can we position the linear regression or linear relationship concept for the age and height relationship above, our answer is different for certain time intervals. I mean, while the height of people increases PROPORTIONALLY for the age range of 0-23 in the widest range, it is fixed for the age-height relationship between the age range of 23-50 and decreases PROPORTIONALLY negatively in the age and height graph after the age of 50. So, can we say that there is linearity in the relationship between age and height for the 0-23 age range, or to put it more clearly, does the height of the person increase by the same amount every year in this time interval, the answer is no. At this point, the age and height relationship does not meet the linearity.

Well, let's talk about what linear relationship-regression is. Let's take the problems we solve in daily life and primary school using the figure 2 graph above. When you go to the market, you see that the price per kilo of apple is $2. If you want to buy 3 kilos of apples, how much would you pay? ' is one of the most basic and simple examples of a linear relationship. For each kilogram increase, the money you will pay to the seller increases at the same rate, that is, 2 dollars more. Here, the linear relationship allows us to accurately predict the next data thanks to the constant increase by looking at the previous data. You know that when you want to buy 10 kilograms of apples, you have to pay $ 20. Because for this example we use the calculation (price= 2 * kg) and call this expression the model later on as things get complicated.

In this article, I tried to explain what Linear Regression is, by supporting it with my expressions and images. Hope to see you in my next post…

What Is Linear Regression?