1. Projects and Strategic Planning:
Projects are often utilized as a means of achieving an organization’s strategic plan.
Projects are typically authorized as a result of one or more of the following strategic considerations: market demand, strategic opportunity or business need, customer request, technological advance, or legal requirements.
Source: A Guide to the Project Management Body of Knowledge (PMBOK® Guide) Fourth Edition ©2008; Project Management Institute

2. Project Portfolios:
A portfolio is a collection of projects or other work that are grouped together to facilitate effective management of that work.
The components of the portfolio are quantifiable; that is, they can be measured, ranked, and prioritized.
The projects in the portfolio need not be interdependent or directly related.
Source: The Standard for Portfolio Management – Second Edition ©2008; Project Management Institute

3. Portfolio Management…
Is a discipline within organizational governance that refers to the coordinated management of portfolio components.
Includes the processes by which an organization prioritizes, selects, and allocates limited internal resources to best accomplish organizational objectives.
Source: The Standard for Portfolio Management – Second Edition ©2008; Project Management Institute