About Project, Program and Portfolio.
Project is an assignment/task/activity to be completed in a specified time, budget and resources with desired quality to create a unique result (product or service). A project is deemed completed when all its objectives are meet with satisfaction to all stakeholders.

According to the author of Head first PMP, the projects ARE

Temporary
Create unique results and
Progressively Elaborated

Projects are NOT

Ongoing processes
Always strategic or critical
Successful

According to PMBOK Guide, Programs are group of related projects with centralized management to achieve company's strategic objectives and goals. These are managed to obtain the benefits and control not achieved while managing them independently. Programs will always have projects, but projects may not necessarily be associated with programs.

PMBOK Guide states that " A Portfolio refers to a group of projects, programs and other works grouped together to facilitate effective management of that work to meet strategic and business objectives. The projects and programs in the portfolio may not be interdependent or directly related."


                            Figure describing the visual contents of Projects, programs and Portfolio.



 Alignment of Project, Program and Portfolio from corporate level to departmental level.



About Project Management and Operation management:

According to PMBOK Guide, Project management is the application of knowledge, skills, tools and techniques to project activities to meet project requirements.Project Management is accomplished through the appropriate application and integration of 42 logically grouped project management processes comprising the five process groups.
The five process groups are

• Initiating
• Planning
• Executing
• Monitoring and Control
• Closing

Managing a project typically includes

Gathering accurate Customer Critical Requirement and Business requirement
Addressing stakeholders, while carrying project through five process groups
Balancing the key constraints such as

• Scope
• Quality
• Schedule
• Budget
• Resources
• Risk
  

Managing a project to ensure a timely delivery of project scope with good quality and within budget is called project management. Operations is a repetitive method which produces same service or product. Effectively delivering the same result without deviation from desired result is called Operation management.
The differences pointed out are that
Projects are temporary and end with delivery of unique product, operations are continuous.
Example:
Project: A plan to start a new Manufacturing Plant.
Operation: The procedure that ensures a finish product is made. A gear manufacturing plant, keeps producing gears following procedures laid out.


Roles of Project Manager in various organizations

Project Manager are provided with varied degree of freedom and responsibilities. Depending on the type of organization,  role of project manager is defined.
According to PMBOK, the following is the relationship between roles of Project Manager and structure of an organization,

Relationship Project characteristics on y-axis and Organization structure on X-axis
	Functional Organization	Weak Matrix	Balanced Matrix	Strong Matrix	Projectized
Project Manager's Authority	Little or None	Limited	Low to Moderate	Moderate to High	High to almost Total
Resource Availability	Little or None	Limited	Low to Moderate	Moderate to High	High to almost Total
Who controls Project's budget	Functional Manager	Functional Manager	Mixed	Project Manager	Project Manager
Project Manager's Role	Part-Time	Part-Time	Full-Time	Full-Time	Full-Time
Project Management Administrative Staff.	Part-Time	Part-Time	Part-Time	Full-Time	Full-Time

Some examples of Functional organizations are Auto Industry and projectized are those with consulting and contract.
Say, Earthmover manufacturing produces oil exploratory equipment. Every time they need to produce a new product In (NPI), modify existing product the Engineering utilizes the project management team in helping them launch new product on time in budget. Here in this scenario, the Project Manager is nothing more than a Project Coordinators or Project Expeditor.
The conditions under which Projects are initiated are as following:

• Developing a new product/ service or Modify an existing product/ Service.
• Bringing in organizational and structural changes.
• Relocation of Organization/ Manufacturing plant or an Assembly Line.
• Building/ Modifying production line(s).
• Introducing new procedures.

Role of Project Management Body of Knowledge.
Role of Project Management's Office (PMO)