Adding teachers to your course allows you and that teacher to be partners in creating the course content.  When you add a teacher to your course, that teacher has full privileges to view, use, and edit the units, lessons, and quizzes within that course.  They are basically co-owners of the course, having all the same privileges as you.  In this way, teachers can share the responsibility of building the quizzes for a course.  You can add as many teachers to a course as you want.  Adding a teacher to your course does not allow that teacher to view your students data, nor can you see theirs.  Only the course content is shared.  Here’s how to add a teacher to your course:

ADDING A TEACHER TO YOUR COURSE

Within Fill, click the UNITS link in the upper left.  Then click the progress bar of the course you would like to add the teacher to.  Click Add Teacher.  Enter the username of the teacher you would like to add.  Then click Add.  The teacher has now has access to the course.