IT asset management (ITAM) is a related but distinct discipline. ITAM focuses on tracking more static hardware and software details throughout the asset life cycle, such as procurement, operation, ongoing maintenance, and disposal. While these details typically include information regarding configuration, a key feature of ITAM is that it focuses on the financial aspects of assets, such as purchasing or licensing costs, depreciation, and replacement costs.
Rather than focusing on business-oriented goals as ITAM does, a CMDB focuses on service-oriented goals, or those that help IT staff understand asset configuration and interdependencies throughout the asset life cycle. A good way to think about the difference between ITAM and a CMDB is to consider an asset that could fall into both categories: a server.
On the ITAM side of things, IT would track when they procured this server, its value and deprecation over time, ongoing operating information (e.g., service agreements) and maintenance costs, and its disposal. IT would also track this server within a CMDB, but this would focus on service-oriented elements like its operation system (OS) and software, firmware versions, and security.