Above is a screenshot from Workspace settings > Notification settings.
Notify users of what's new in the workspace
All notifications to all users
When this option is selected all users in the workspace will receive notifications of both personally relevant acitivity and activity that does not directly relate to them. It is a good option to choose with smaller workspaces where it is important for all users to know about all other comments and activity.
All notifications to admins, only personal notifications for participants
This option notifies admin users of all the activity even if it is not personally relevant to them, however participants only get notified of activity related to them. This is a good choice in medium - large workspaces where admins need to be aware of all comment, replies, likes etc. but it is more important for participants to know about discussions relevant to them.
Only personal notifications to all users
All users (admins & participants) only get shown notifications that directly relate to them. This can be a good choice in large workspaces with many different discussion and topics going at the same time.
What's new summary email frequency
How often the automatic summary emails are sent from the workspace to the users (both admins and participants). Options are Immediately / Daily / Weekly / Never. The summary email informs the user of how many unread notifications they have in the particular workspace.
All users have an ability to set their own preference in their user profile notification settings.
Personal email notification
This is an email that is sent out immediately when there is a reply or like to a comment that the user has been participating in. This email is sent only when there is a personal notification for the user, while they are not online. Only 1 email will be sent within 12 unless the user visits the workspace.