Is sponsor internal to organization or can be customer?

Bhavna -

Sponsor is a role, and there can be internal and external sponsors for projects. In a very simple case, the customer can be the same as the sponsor and hence, by definition, external. For example, if I am getting my backyard deck built, I am the customer and sponsor of the project as I'm both providing the requirements for the product to be built and am providing the funding and acting as the "champion" for the project.

Kiron

It can be both internal and/or external.