An author plans to change the source pages that occur as a result of normal...

Creating a Launch:

Authors can create a launch from the existing live content. This copy is separate from the live site and can be modified without affecting the live version.

Making Changes:

The content in the launch can be edited, and changes can be tested and reviewed within the launch environment.

Promotion:

Once the updates are approved, the changes can be promoted from the launch back to the live site. This process updates the live content with the changes made in the launch.

References:

AEM Documentation on Launches

Launches are designed specifically to manage scenarios where authors need to handle multiple branches and promote changes seamlessly.