This ERD example shows the typical business entities of a college. A college contains many departments which can offer any number of courses. Many instructors can work in a department and an instructor can work only in one department. For each department there is a Head. An instructor can be head of only one department. Each instructor can take any number of courses, but course can be taken by only one instructor. A student can enrol for any number of courses and each course can have any number of students.
