ISO/IEC 20000-1 is a certifiable management system standard, while ITIL is a best-practice framework for IT service management. ITIL provides guidance on how service management practices can be designed and improved. ISO/IEC 20000-1 defines the formal requirements an organization must meet to achieve certification. Many organizations use ITIL practices to support ISO/IEC 20000-1 implementation, but the two are not the same.