When programming events for a component, the order of actions for an event is important in determining the behavior of the component. For example, consider a login button that has 2 active actions for its On Click event: (1) Function call to authentify the user, and (2) Navigation to a home page. If (2) comes before (1) in the Actions contextual panel, the user would always be re-directed to the home page before their credentials could be verified. That would not be the desired behavior.
This could be fixed by removing both actions and creating them again in the correct order. However, it would be easier to re-order the actions by clicking on the drag handle icon and dragging the action box.
This way, when the login button is clicked, the authentify action would be called first, and in case it throws an error, the navigate action would not be triggered.