IT Service Management/ITSM
ITSM (IT Service Management) is a generic term describing the field of Service Management as applied to providing IT Services.
ITIL, on the other hand, is a specific, branded framework of guidance that is owned and managed by Axelos.
ITIL is one of several IT Service Management frameworks/models. It is the most widely used and accepted of the published frameworks.
The goal of every IT Service Management framework is to ensure that the right processes, people and technology are in place so that the organization can meet its business goals.
The primary focus is always to keep the goal of maximum business value in mind. Frameworks can help, but must never become the goal in themselves. Organizations must determine the right balance of framework(s) and parts to adopt to meet their business needs.