Final answer:
The grid settings change automatically when the Main Time Scale is changed because they are linked to each other, ensuring a consistent and coherent user experience in the software application.
Step-by-step explanation:
The grid settings on a user interface or in a software application, particularly those related to timelines or schedules, are often linked to the Main Time Scale. This means that when changes are made to the Main Time Scale, the grid settings automatically adjust to reflect those changes. This ensures that the visual representation of time on the grid is consistent with the scale set by the user. It is a feature designed to provide a coherent user experience, so that as the timescale is zoomed in or out, the grid adapts accordingly, maintaining the relationship between the time intervals and the visual grid lines.