The major difference between a CMDB and an asset register is that CMDB holds information on:

The primary and most significant difference between a Configuration Management Database (CMDB) and an asset register lies in the CMDB's function to store and map the relationships and dependencies between its components, known as Configuration Items (CIs). While an asset register is a list focused on the financial and lifecycle aspects of assets (e.g., cost, owner, purchase date), a CMDB provides a logical model of the IT infrastructure. This relational data is essential for understanding how CIs work together to deliver services, enabling critical processes like impact analysis for changes, root cause analysis for problems, and service restoration.

A. Documentation: Both systems can store or link to relevant documentation for the items they track.
B. Software: Both an asset register (for license and cost tracking) and a CMDB (as a CI) can contain information about software.
C. The IT environment: This is too general; both tools manage components within the IT environment, but from different perspectives (financial vs. operational).

1. AXELOS. (2019). ITIL® Foundation, ITIL 4 Edition. TSO (The Stationery Office).

In Section 5.2.5, "Configuration management," the text explains that a CMDB is a database used to store configuration records throughout their lifecycle, emphasizing that it "also stores information about the relationships between CIs." This is contrasted with IT asset management, which focuses on financial value.

2. ISO/IEC 20000-1:2018, Information technology — Service management — Part 1: Service management system requirements.

Section 8.2.5, "Configuration management," mandates that an organization must identify, control, and record CIs, and specifically "define and maintain the relationships between configuration items." This highlights relationships as a core, standardized requirement of a CMDB.

3. Iden, J., & Langeland, O. (2010). Setting the Stage for a Successful ITIL Adoption. In Proceedings of the 43rd Hawaii International Conference on System Sciences. IEEE.

The paper discusses the implementation of ITIL processes and notes that the CMDB's value is derived from its ability to provide a holistic view of the IT infrastructure, which is achieved by mapping the "interdependencies between the different components" (p. 4). This academic source reinforces that relationships are the key differentiator and value proposition.