projects:
projects have definitive starts, pass through a number of stages and come to an end. They consume resources of people, equipment, materials and money. The management of projects concentrates on delivering products or deliverables.

programmes:
programmes are usually a collection of separate but interdependent projects to achieve the overall targets. The management of programmes frequently concentratrates on the interfaces between the separate projects and focuses on the benefits to be achieved overall.

portfolios:
portfolios are usually collections of projects which are not directly related or dependent on each other except for common aspects such as funding, or types of work, or shared resources. The management of portfolios concentrates on overall efficiency, effectiveness and/or profitability.

multiple projects:
multiple projects are a reflection of modern living including multi-tasking with limited resources. Individuals and groups undertaking multiple projects need to allocate their attentions and efforts to suit changing circumstances, combinations, pressures and priorities across the day, the week, the month, the year.