ITIL is a framework for ITSM or information technology service management. In ITIL 4, service management is the capability of an organization to give value to customers in the form of services. Whenever we mention organizational capability, this refers to an organization having both the capacity and the ability to perform the functions required.
Performing service management is focused on how to best create value within an organization to provide the desired benefits to consumers regardless of whether ITIL 4 or another ITSM framework is being used. The organization must organize its people to best support the organization's activities, practices, and processes. These activities, practices, and processes are the engines that drive the creation of the organization's products and the services they are capable of delivering. But, none of these could be done in isolation. We have to consider the service relationships that are built, created and nurtured throughout the service management process. The generalized concepts of service management apply to both ITIL 4 and other frameworks.