You can draw Connection lines from one Task to another to show dependencies. Hover over a Task until the circular pin appears on the top and then drag it to another Task.
Figure 1. Connecting Tasks
You can further customize the connection by clicking directly on the line and choosing from the pop-up. You can change the style and color of the line or delete it.
Figure 2. Changing Connection Style
🚧 Caution: Make sure you are drawing the lines from left to right to show the correct flow of time. They cannot overlap, otherwise both Tasks will glow red, denoting a conflict as dependent Tasks cannot occur simultaneously.