The Early Warning System is a tool that allows instructors to create rules to send notification messages to students and observers based on factors like test scores, assignments, or course access. It aims to define the EWS, explain its limitations and advantages, and demonstrate how to access the tool and create rules. Instructors can establish rules that are triggered based on set criteria, like a low test grade. The system is meant to forewarn students and help keep them on track by notifying them and others of issues or areas for improvement.