Comments strategy (☰ → Features/Strategies → Comments) lets you add Comments to Tasks and Projects. It's similar to Task Notes except that Comments keep track of who created them and when. This is especially useful when you use Task Sharing!
You can then click on the "Open Comments" hover menu/right-click menu button to open comments.
Doing this will open the Comments tab in the Open Task dialog which is another way to access your comments. There you will see a list of all comments added to the task you opened, both comments created by you and by others with whom you shared the task.