When you add information to staff details for an instructor/a teacher (see below), there are specific places on your public site that this information will be visible.
On your public page, when a registrant clicks the name of the instructor in the class listing...
that takes the registrant to the staff detail page for that instructor. The staff details that were entered into the staff details for this particular instructor will be visible her.
Also, if you are using the reservations module, any staff details for the instructor that is visible will be available.