This sample demonstrates the rendering of critical path to the Gantt control.
In this example, you can see how to render a Gantt chart with critical path. The default timeline view week-day mode is applied to Gantt chart. The dependency lines are enabled in this example to represent the execution order or the hierarchy between the phases.
The critical path is a series of tasks (or sometimes only a single task) that controls the calculated finish date of the project. If a task in a critical path is delayed, then the entire project will be delayed.
More information on the Critical Path feature can be found in this documentation section.