2. Milestone– a task, scheduled for a certain date and used to control the project status on that date. To learn more, see the respective Help section.
3.Sub-project – a task with limited duration, which includes a list of tasks of different types. To learn more about creating a sub-project, see the respective Help page.
The set of toolbar buttons on the page depends on the task type, user's role and access permissions. To learn more, see the pages on the respective task types.