The "Watch Discussion" option allows you to be notified if someone has responded on a discussion. By selecting "watch discussion" on any given discussion and setting your Alert Preferences in your personal settings, you will be notified through your course profile alerts and/or personal email, making sure you don't miss any activity in your discussions.

To watch a discussion, open any discussion you want to be notified of by clicking on the title (this is also how to reply to a discussion)


Above the discussion, to the top right, click Watch Discussion


Select your preference in the pop up. Email notifications will go to the email on file for your account

Click Watch Discussion to save 

Go to your Preferences to set them for watched discussions.
Mouse over your name in the top left corner and click on Preferences


The select Alerts Preferences from the bottom of the left side 


Check what alerts you want to receive about Messages in Section Discussions. The Replies and Attached File alerts are for discussions you're watching

Click Save

Alerts appear in a red box next to your name in the top left corner of the screen


Hover over "Alerts" to see recent activity


This is also another place you can access your Alert Preferences


To Unfollow a discussion go back to the same place you followed it


A confirmation prompt will appear. Click Stop watching to confirm the action