A group of related projects and activities that are managed together to reach a larger, overarching set of objectives.
Classic examples include the development of a new line of cars, where the range = the program (e.g. the Ford Focus), and the model = the project (e.g. the Ford Focus Zetec Navigator); or the launch of a new airplane (the program), where each feature or system will be a project.
A program is focused on a tactical goal, on how the projects are carried out. By contrast the portfolio is concerned with strategic goals: which projects and programs to carry out, who should get priority for resources etc.
see also: project portfolio