Transitions control the flow of the chart. A transition serves to either block or allow flow, depending on its value. All transitions have a value: true or false, which is determined by an expression. Transitions occupy a one-cell region of the chart, and are represented by a short horizontal bar in the middle of the cell. Read more about how transitions control chart flow in the Chart Flow and Rules section.
In addition to their expression, a transition can also specify a timeout. If enabled, the transition will set a flag after a certain amount of time has passed. This flag is a boolean variable set in chart scope, and can be used to make the expression or another expression close.
A link is simply a line that connects other elements. Links are created in the Designer by dragging the arrows that appear next to unconnected elements. Links cannot cross above or below other elements or links. Links only travel in a single direction. This direction is determined by what the link is connecting to. Most elements such as steps and transitions only accept incoming links from above and outgoing links from below.