What is ITSM

ITSM is 

(1) Best Practices

(2) Non-prescriptive

(3) Non-proprietary

Best practices - compiled experiences and success factors from various organizations over decades

In the end ITSM provides a framework that is descriptive

This framework has to be adopted by an organization and accordingly adapted to the particular organization. How it is adapted is left to the organization - It is NOT a HOW TO DO.

HOW TO DO is actually implementing

Adopting is NOT implementing ITIL. (because ITIL is a set of best practices)

Adopt is about governance required to manage IT services. Now to implement governance your require policies, and this results to an organization adapting to ITIL.

ITSM is a management system.

Comparison with COBIT

The process focus of COBIT is modelled via a process model that subdivides IT into four domains PBRM Plan Build Run Monitor

Plan and Organize

Acquire and Implement

Deliver and Support

Monitor and Evaluate

and its Governance with EDM     Evaluate, Direct, Monitor

Evaluate -   Identity and agree on objective that must be achieved

Direct      -   through prioritisation and decision making

Monitor  -  Performance and compliance against objectives

and 34 processes inline with the responsibility areas of plan, build, run, and monitor. It is positioned at a high level and has been aligned and harmonized with other, more detailed IT standards and good practices such as COSO, ITIL, BiSL, ISO 27000, CMMI, TOGAF and PMBOK. COBIT acts as an integrator of these different guidance materials, summarizing key objectives under one umbrella framework that link the good practice models with governance and business requirements.

COBIT is 5 Principles and 7 Enablers