ITIL, formerly known as the Information Technology Infrastructure Library, is a set of practices for IT service management (ITSM) that focuses on aligning IT services with the needs of business. In its current form (known as ITIL 2011 edition), ITIL is published as a series of five core volumes, each of which covers a different ITSM lifecycle stage. Although ITIL underpins ISO/IEC 20000 (previously BS15000), the International Service Management Standard for IT service management, there are some differences between the ISO 20000 standard and the ITIL framework.

ITIL describes processes, procedures, tasks, and checklists which are not organization-specific, but can be applied by an organization for establishing integration with the organization’s strategy, delivering value, and maintaining a minimum level of competency. It allows the organization to establish a baseline from which it can plan, implement, and measure. It is used to demonstrate compliance and to measure improvement.

Since July 2013, ITIL has been owned by AXELOS Ltd, a joint venture between HM Cabinet Office and Capita Plc. AXELOS licenses organisations to use the ITIL intellectual property, accredits licensed Examination Institutes, and manages updates to the framework.