When you link tasks, you create scheduling relationships between the tasks. These task relationships are called dependencies, as in the start of this task is dependent upon the completion of a prior task. When you create task dependencies (also called links), Project can automatically adjust the scheduling of linked tasks as changes occur in your plan. Creating dependencies by linking tasks is crucial to getting the full benefit of the Project scheduling engine.
This topic will cover the task relationships supported by Project and typical usage scenarios, methods to link and unlink tasks, as well as auto-scheduled tasks and switching between manual and automatic mode.