PMBOK

Definition: PMBOK is an internationally recognized standard (IEEE, ANSI and ISO 21500) that deals with the application of knowledge, skills, tools, and techniques to meet project requirements.
The P Guide defines a project life cycle with 5 process groups, 10 knowledge areas and 47 processes of the project management profession.

More on pmbok.
More on project management: PRINCE2, Project Management, Project Termination, RACI.

MBA Brief offers brief, yet very accurate definitions of MBA concepts, frameworks, methods and models. We keep it short and provide some links in case you'd like to learn more around a subject.