Change management' is defined as the means by which an organization transitions to a desired future state. It involves the processes and techniques used to manage the people side of change to achieve the required business outcome, ensuring that changes are implemented smoothly and effectively.References: PRINCE27 Foundation materials on project management terms and definitions.

Reference https://www.prince2primer.com/prince2-roles-and-responsibilities/

The purpose of the Directing a Project process is for the Project Board to delegate the day-to-day management of the project to the Project Manager, providing the overall direction and management of the project lifecycle.
This process is critical for enabling the Project Manager to run the project on behalf of the Project Board within the constraints set out by them. References: PRINCE2Foundation official documentation and study materials.