There are a few different roles that members can play inside each Course. For each of these options, there can be an unlimited number of folks designated in this role, including Instructors.
Here's a breakdown of each role.
A Course Host controls everything about the Course—privacy settings, general settings, the Topics in the course, design, the features that are turned on and off for members, and the Course Overview. Someone who is a Course Host can also invite and remove members, designate someone as a Course Moderator or Instructor, and moderate all the content and activity in the Course Activity Feed.
Course Moderators have the ability to edit and moderate all of the content and activity in the Course Activity Feed. They can also manage Topics and adjust the features that are turned on in the Course for members to use (like polls and questions, articles, and events). By default, they do not have the ability to edit the Course Overview or any of the Sections or Lessons in the Course.
To make someone a Course Moderator, navigate to Course Members > search for their name > select the More Menu > Change Role > choose Course Moderator.
Course Instructors have the ability to edit individual Lessons inside a Course. To assign someone to be an instructor of your Course, you need to first make them a Course Moderator (see above). Then, you can assign them to an individual Lesson. To do this, go to the Lesson you would like to assign to them > select the More Menu > choose Assign Instructor.
Once they are the Instructor of at least one Lesson, the Course Overview will show them as an Instructor of the Course as a whole.
Note that a Course Instructor will only be able to edit the Lessons they have been assigned. They will be able to populate the Lesson, make the Lesson visible, and turn comments on or off.
The Instructors of a Section will reflect the Instructors of the Lessons that are inside of that Section. If all of the Lessons inside a Section have the same Instructor, the Section will only have one Instructor. If the Lessons inside a Section all have different Instructors, all of those Instructors will show up as the Instructors of that Section.
The same applies to Instructors of a Course. The Instructors of a Course will reflect anyone who is an Instructor of a Lesson inside of that Course.
Instructors are not able to edit the Course Overview or individual Sections within a Course. If you would like to give someone permission to edit the entire Course—including the Course Overview and Sections—make them a Host of your Course by going to Course Members > search for their name > select the More Menu > Change Role > choose Course Host.