UPDATED VERSION OF THIS VIDEO FOR 2023! Check it out here: https://www.youtube.com/watch?v=eYTumjgE2IY All videos here: http://www.zstatistics.com/ The first video in a series of 5 explaining the fundamentals of regression. See the whole regression series here:    • Regression series (10 videos)   Please note that in my videos I use the abbreviations: SSR = Sum of Squares due to the Regression SSE = Sum of Squares due to Error. Intro: 0:00 Y-hat line: 2:26 Sample error term, e: 3:47 SSR, SSE, SST: 8:40 R-squared intro: 9:43 Population error term, ε: 12:11 Second video here: https://www.youtube.com/watch?v=4otEcA3gjLk Ever wondered WHY you have to SQUARE the error terms?? Here we deal with the very basics: what is regression? How do we establish a relationship between two variables? Why must we SQUARE the error terms? What exactly is SSE, SSR and SST? What is the difference between a POPULATION regression function and a SAMPLE regression line? Why are there so many different types of error terms?? Enjoy.