Predecessors Tasks that link to and come before the selected task.
DrivingPredecessors Tasks that come before the selected task and directly impact it. When the driving predecessor task moves, the selected task also moves.
Successors Tasks that link to and follow the selected task.
Driven Successors Tasks that follow the selected task and are directly impacted by it.
When the selected task moves, the driven successor task also moves.
This image shows that predecessors and successors are highlighted on the GanttChart.