What's the difference between a business unit and a project unit?

Use business units to control and report on financial transactions. For each business unit, you configure fundamental operating settings to control project setup, expenditure processing, and cross-charge transaction processing.

Use project units to enforce consistent project management practices for projects across multiple business units. For each project unit, you configure project management settings such as the default set assignment, project numbering series, full-time equivalent hours, related business units, and reporting options.