1. ITIL Service Value System (SVS): The ITIL SVS represents how all the components and activities of an organization work together to facilitate value creation through IT-enabled services. It integrates various elements such as guiding principles, governance, service value chain, practices, and continual improvement into a unified system that ensures consistent and effective service management.

2. Service Value Chain: The service value chain is a key part of the SVS and outlines the main activities required to create and manage products and services. It includes six interconnected activities:

• Plan: Ensuring a shared understanding of the vision, current status, and improvement direction.
• Improve: Ensuring continual improvement of products, services, and practices.
• Engage: Understanding stakeholder needs and ensuring transparency.
• Design and Transition: Ensuring that services meet expectations for quality and performance.
• Obtain/Build: Ensuring service components are available as and when needed.
• Deliver and Support: Ensuring services are delivered and supported according to agreed specifications and stakeholder expectations.

3. Four Dimensions Model: The Four Dimensions Model ensures a holistic approach to service management, considering all aspects necessary for successful service delivery and value creation. The four dimensions are:

• Organizations and People: Ensuring effective structure, culture, roles, and skills.
• Information and Technology: Managing the information and technologies that support service management.
• Partners and Suppliers: Working effectively with suppliers and partners to ensure smooth service delivery.
• Value Streams and Processes: Optimizing workflows and processes to deliver value efficiently and effectively.

These core concepts form the foundation of ITIL 4, guiding organizations to align their IT services with business needs and drive continuous improvement.