A group of related projects managed in a coordinated way to obtain benefits and control not available from managing them individually. Programs may include elements of related work outside of the scope of the discrete projects in the program.(PMI 2008)
PMI. 2008. A Guide to the Project Management Body of Knowledge (PMBOK® Guide), 4th ed. Newtown Square, PA, USA: Project Management Institute (PMI).
The term "program" is also used as another name for a large project. "Program management" is sometimes used to denote management of a portfolio of projects within a business unit.