How do I logout multiple users on iMac

Hello nealfrommillsboro,

Thanks for using Apple discussions. You can log out of users by logging-in to their desktop and logging out. If you're familiar with Activity Monitor you can stop their tasks by following the steps below:

1. Run Activity Monitor.
2. In the filter at the top-right, type loginwindow.
3. Click the row with the user's name in the User column.
4. Click Quit Process, then Force Quit, and type your password.