The Information Technology Infrastructure Library, commonly known as ITIL, is a set of best practices for managing information technology services. ITIL is a non-organization specific set of tasks, procedures and checklists for establishing a minimum level of competency. Further, it allows any organization to set a baseline against which it can plan, implement and measure the effect of changes made.

ITIL has been published as a series of books, covering each aspect of Information Technology Service Management. Both the names Information Technology Infrastructure Library and ITIL are registered trademarks of the UK government. In the 1980s, the UK government realized that various government departments and private sector organizations were developing their individual set of standards for managing information technology departments, and started investing in and using IT services. But they were always at a loss as to how to derive the maximum benefits out of them and how to make the methods and standards common place across the industry.

Because of this, the UK government's Central Computer and Telecommunication Agency decided to develop a set of recommendations. The Information Technology Infrastructure Library was published as a series of books, each covering a specific set IT processes. This set soon grew into 30 books, and in 2000-2001 the books were consolidated into 8 volumes, making them more accessible and affordable for those seeking training.

Ever since, these books are constantly reviewed, changed, and refined in order to keep abreast with the dynamic developments in the IT sector. The latest 2011 edition focuses on 26 processes carried out in IT, and have been consolidated into 5 volumes. The core books are as follows: Service Strategy, Service Design, Service Transition, Service Operation and Continual Service Improvement.

Aside from this set of core books, there are other books published, relating to IT service management and operational guidance as well. The service support book, for example, focuses on users who have access to the appropriate IT services to support their business functions.

ITIL supports the notion that the primary role of IT is to provide support to the business needs of the organization. It also guides businesses in how to utilize IT as a tool to streamline business, facilitate, and help its growth. By adopting ITIL, organizations have reaped huge benefits in the following areas of business:

1. Improved IT services

2. Reduction in costs

3. Increased customer satisfaction

4. Productivity improved

5. Better use of employees' skills and experience

A number of world-renowned organizations and various countries governments have since adopted ITIL, and are deriving the maximum benefit from the usages of new systems and best practices for benefiting from the above.