This seems like a lot, I know, but don't panic! This material can be quite confusing the first time you see it, and I don't want you to lose faith in yourself. You'll see other confusing topics as we progress, but knowing you have this figured out will give you confidence moving forward. So keep calm, and carry on!
My video lesson is the first one you'll see below. There are also three quick videos by the author that describe the same topics. Also, the author has what he calls "screencasts" that are similar to my video lessons. They are here: SCREENCAST #1, and SCREENCAST #2. Just click on the blue words to see the screencasts.
Source: (c) 2016, Pearson
Source: (c) 2016 Pearson
Source: (c) 2016 Pearson
Source: (c) 2016 Pearson