What is the difference between, Project, program and Portfolio?

Hello Sir,

See answer below. Regards, Stylianos

Project: Purpose,  Applies and uses project management processes, knowledge, and skills Area of focus: Delivery of products, services, or results. 

Program: Purpose, Collections of related projects, sub-projects, or work managed in a coordinated fashion. Area of focus: Project inter-dependencies. 

Portfolios: Purpose,  

Aligns projects/programs/portfolios/sub-portfolios/operations to the organization's strategic business objectives. 

Area of focus: Optimizing efficiencies, objectives, costs, resources, risks, and schedules.