According to the PMBOK® Guide and The Standard for Portfolio Management, the relationship between portfolios, programs, and projects is defined by their focus on organizational strategy.

Portfolio Definition: A portfolio is defined as a collection of projects, programs, subsidiary portfolios, and operations managed as a group to achieve strategic objectives.

Strategic Focus: The components of a portfolio may not necessarily be interdependent or directly related. However, they are linked to the organization ' s strategic plan by the way they compete for the same resources and contribute to the same high-level business goals.

Portfolio Management: This involves the centralized management of one or more portfolios to identify, prioritize, authorize, manage, and control projects and programs. The primary goal is to ensure the organization is doing the " right " work to maximize the value of its investments.

Comparison with other options:

A. Plan: A plan (such as the Project Management Plan) is a formal document used to guide execution and control. It is a tool for a specific project or program, not a collection of them.

B. Process: A process is a systematic series of activities directed toward causing an end result where one or more inputs will be acted upon to create one or more outputs.

C. Program: A program is a group of related projects, subprograms, and program activities managed in a coordinated way to obtain benefits not available from managing them individually. Wile it is a collection of projects, its focus is on synergy and coordination between related works, whereas a portfolio is focused specifically on strategic objectives.