Organizational Governance is same as Corporate governance.
Governance is a mechanism for monitoring the actions, policies and decisions of corporations. Governance involves the alignment of interests among the stakeholders.

Governance provides the structure through which corporations set and pursue their objectives, while reflecting the context of the social, regulatory and market environment.

Corporate governance refers to the system of structures, rights, duties, and obligations by which corporations are directed and controlled. The governance structure specifies the distribution of rights and responsibilities among different participants in the corporation (such as the board of directors, managers, shareholders, creditors, auditors, regulators, and other stakeholders) and specifies the rules and procedures for making decisions in corporate affairs

Project governance is the management framework within which project decisions are made. Project governance is a critical element of any project since while the accountabilities and responsibilities associated with an organization’s business as usual activities are laid down in their organizational governance arrangements, seldom does an equivalent framework exist to govern the development of its Projects

For instance, the organization chart provides a good indication of who in the organization is responsible for any particular operational activity the organization conducts. But unless an organization has specifically developed a project governance policy, no such chart is likely to exist for project development activity.

Therefore, the role of project governance is to provide a decision making framework that is logical, robust and repeatable to govern an organization’s capital investments. In this way, an organization will have a structured approach to conducting both its business as usual activities and its business change, or project, activities.

Source - Wikipedia.

Nothing else to add. Great job of referencing.