A design system is a systematic approach to achieving consistent look-and-feel across the product(s) of a company.

This is in contrast to the "non-systematic" approach, which is to have designers use apps like Photoshop to copy-paste design elements and then have developers eye-ball and eye-drop that into code. You may up with lots of redundant definitions for essentially the same visual intent, especially with larger teams.

Most products start out with the non-systematic approach and then may later attempt a switch to a design system. Presumably, this is where this product could help you validate your progress. Whether integration of such a product is a valuable addition to your workflow or a distraction is up for debate.