Four of the folders here correspond to a project in the book. As you read the book, you should add scripts to these folders. That will help you understand what the different projects teach. Other folders aren't projects. They store files used as examples throughout the book. The first two project files have subfolders named 'snapshots'. If the book says, "make a script that does X", you try, but you can't get the promised result, you can copy those files up into the main folder to get yourself moving again. However, I *strongly* urge you to type the script yourself. If you always just copy it in, you won't build any "muscle memory" of typing Ruby and you'll have a hard time with your real scripts.