CentreStack is and Enterprise File Sync, Share, and Collaboration Platform. Guest users are users that are not in the system but can receive files or folders shared from other users in the system. when guest users are granted full access permission with read and write control, guest users are able to access the shared file via email and are able to update and add comments to the shared file. Once the comments are updated the admin or the user who shared the file can see the updated comments for the shared file from their web portal.
The video below will demonstrate how guest users can update comments for shared files and how the guest user account is created.