What’s the difference between a primary tour and a general tour?

The difference between a primary tour and general tour is that a primary tour is specialized—it holds settings to manage the Help Menu for its respective app. You can configure whether a tour is general or primary either when you’re adding the tour: 

Or in the details of the tour:

Each app can only have one primary tour. You’ll find the Primary Tour Settings in any primary tour’s details. 

Here, you can adjust the Help Menu for the respective app. You can change the caption at the top, the description of the app, the colors of the popup, and the app image if necessary.