What does starred mean?

The starred concept is meant to help you mark important items. You may add a star to a task, milestone, message, whiteboard or to a file by clicking on the star icon next to each item. This will make that item stand out from the crowd.

Can I see a list with all my starred items?

You may see a list of your starred items by accessing the star tab on the right part of the navigation menu. The list is available for a single project, as well as for multiple projects. In the starred items page you also have the option to filter the list by item type.