You can edit the Task Name, Points, Percentage Complete, Start Date, End Date and Blocked fields inline. You can edit the remaining fields on the Edit popup.
To edit the details of a project taskA unit of work or collection of work associated with a project. inline:
To view the details for project tasks using the Edit popup:
Concept Information
Related Tasks
Assigning Resources to a Project Task
Marking Tasks as Blocked or Unblocked
Removing Resources from Project Tasks
Viewing Detailed Task Information
Reference Materials