Outsourcing vs Shared Services

From my experience....

Outsourcing means you are taking a function of the company / business, and contracting another party to run it. For example, outsourcing your Service Desk.

Shared services usually refers to a service provided within the company, whether outsourced or not, that goes across business units. For example, if your company has one HR department at the corporate level for all business units, it is considered a shared service.