ITIL (Information Technology Infrastructure Library) is a set of best practice standards for Information Technology Service Management (ITSM). The United Kingdom's Central Computer and Telecommunications Agency (CCTA) created ITIL during the late 1980's in response to the growing dependence on Information Technology to meet business needs and goals. As a result of widespread adoption and continuous improvement, ITIL has become the de facto standard in service management. ITIL provides businesses with a customizable framework of best practices to achieve quality service and overcome difficulties associated with the growth and complexity of IT systems.

ITIL is organized into sets of texts which are defined by related functions: service support, service delivery, security management, infrastructure management, application management and others. Service Management, the heart of ITIL, addresses a variety of IT functions that can be effectively categorized into two groups: Service Support and Service Delivery.