So, what we're going to see is an example in which
we're going to have as a base class a student.
And we're going to think about this in a point of view,
well, course I've been at the University of California for ever.
When you build big data base for something like
university, university has all different categories
of people on the campus.
There are students, there are special kinds of students, so there,
are generic students but then there might be a graduate student.
There might be even further subdivisions of students.
There might be students who are in special categories, like professional
students, like online students that are, have different characteristics.
And, indeed you could even think of something more basic if
you were building some big database for your university such as person.
So, if you had person, then you would have not only student,
but you might have employee, and
among employees you would have different categories.
Again, this would give you a development, model.
For building a system
that would reflect and model, and let you implement stuff you needed for
working with, everybody on the university campus.
So, you'd have employees, some of the employees would be academic.
In the academic employee, there would be.
Possibly tenure track and non-tenure track faculty.
And then on the employee staff there might be professional staff, business
staff.