Akhil,
The difference is really quite simple:
Enterprise Environmental Factors: This includes everything from inside or outside of your company that influences your project. Internal factors could be your company culture or structure. External factors could be the economy or union contracts.
Organizational Process Assets: These are all of your company's policies and procedures. For instance your project must follow the documented process of how people are hired for a project and you must also implement your company's quality policy on your project.