CSS Grid Layout in and of itself is amazing. However, it is not the end to all ends. With more and more technolgies hitting the market each year, the screen size and use of the device changes. With that, a web page needs to be able to respond depending on the screen size it is brought up in. We are talking from monster screens to very little screens, like an iWatch. And the web page needs to be dynamically responsive.
Eventhough most of the content resides on the cloud, there are times when a user will want or need a hard copy of the information presented and doesn't need/want everything to print; such as navigation, advertisements, and so on. But there are some items that need to print; such as the url behind a link. And that is where Print Style Sheets are used. Print Style Sheets define how all of that is handled when the user selects print through the browser.