The Lock feature allows you to schedule class lock dates/times and to have more control over posts while your class is locked.  Locking a class makes the class Inactive, disallowing students from posting or editing content within the course.

Locking a class also prevents anyone from enrolling in your course. 

If you need to quickly lock your entire class, you can do so by clicking the lock icon next to Class at a Glance, which will display the following options:

If you select 'Lock this class immediately' you will see three options: 

'Lock this class, no posts allowed' - students will be unable to post while the class is locked

'Lock this class, block access to all posts' - students will be unable to view posts while the class is locked

'Lock this class, private posts to instructors allowed' - students will be able to post privately to instructors while the class is locked 

If you select 'Schedule future lock dates/times' it will redirect you to the ‘Manage Class’ tab to schedule class lock dates/times (say, when you are holding tests). Selecting 'Add another lock date/time' will open up the following options:

In addition to locking a class, you are able to lock individual posts, say if you no longer want students to be able to contribute to that post. By clicking on the lock icon you will see two options:

'Lock this post immediately' - the post will immediately be locked 

'Schedule future lock date/time' - you can select the time/date for this post to be scheduled to lock