1. WHAT IS A PROJECT ?
A project is a temporary endeavor undertaken to create a unique product, service, or result.
Source: A Guide to the Project Management Body of Knowledge (PMBOK® Guide) Fourth Edition ©2008; Project Management Institute

2. Temporary means that every project has a definite beginning and a
definite end.
The end is reached when a project’s objectives
have been achieved, or…
it becomes clear that the project objectives will not or cannot be met, or
the need for the project no longer exists.
Source: A Guide to the Project Management Body of Knowledge (PMBOK® Guide) Fourth Edition ©2008; Project Management Institute

3. A project creates a unique product, service or result…
Repetitive elements may be present in some project deliverables.
The presence of repetitive elements does not change the fundamental uniqueness of project work.
Source: A Guide to the Project Management Body of Knowledge (PMBOK® Guide) Fourth Edition ©2008; Project Management Institute

4. Projects vs. Ongoing Work …
Ongoing work effort is generally a repetitive process that follows an organization’s existing procedures.
Because of the unique nature of projects, there may be uncertainties about the products, services or results that the project creates.
This requires more dedicated planning than other routine work.
Source: A Guide to the Project Management Body of Knowledge (PMBOK® Guide) Fourth Edition ©2008; Project Management Institute