Within the Gantt, you can view a highlighted Critical Path.
A Critical Path is a sequence of Tasks that cannot be delayed. They rely upon each other’s on-time completion, and a delay would lead to Dependencies jeopardising the entire timeline. A delayed Critical Path means a delayed Project.
A Task is considered Critical if it has no days of slack and any delay would directly affect the Project completion date. Slack time is the time that a Task can slip without affecting other Tasks or the Project’s completion date.
Simple toggle the Critical Path on or off in the ‘Gantt Options’ bar.