This is a brief catch-all section designed to make sure you understand not just what elements and selectors and attributes you CAN use, but which ones you SHOULD use in each situation. When you go visit several “normal” webpages (preferably one that isn’t too massively corporate, since they do some abnormal stuff), there are a lot of similarities in the way they are structured (which you can see in your developer tools). They all tend to judiciously use container divs for grouping elements and they use classes and IDs as necessary to determine styles.
You’ll also get the chance to review what was covered in previous sections by checking out LearnLayout and doing their exercises.
This section contains helpful links to other content. It isn’t required, so consider it supplemental for if you need to dive deeper into something.