Let's talk about regression analysis, a very popular topic in data science and statistics. It's all about trying to fit a curve or some sort of function, to a set of observations and then using that function to predict new values that you haven't seen yet. That's all there is to linear regression!
So, linear regression is fitting a straight line to a set of observations. For example, let's say that I have a bunch of people that I measured and the two features that I measured of these people are their weight and their height:
I'm showing the weight on the x-axis and the height on the y-axis, and I can plot all these data points, as in the people's weight versus their height, and I can say, "Hmm, that looks like a linear relationship, doesn't it? Maybe I can fit a straight line to it and use that to predict new values...
