Consider a hypothetical online management system for the Saudi Electronic University that uses a relational database to manage its operations. This system needs to keep track of information about students (including student ID, name, major, and email), courses (including course ID, name, instructor, and department), and enrollments (including enrollment ID, student ID, course ID, grade, and semester). Describe how you would design the relational model for this system. What tables would you create? What attributes would each table have? How would you use primary and foreign keys to represent relationships between the tables?