What is CMDB (Configuration Management Database)?

A CMDB (Configuration Management Database) is a repository that records the components of an IT environment, known as configuration items, or CIs, such as servers, applications, network devices, and services, together with the relationships and dependencies between them. The relationships are the point: a CMDB can show that a particular app depends on a specific server, switch, and database.

Why it matters: knowing how things connect makes impact analysis, change planning, and incident diagnosis far safer, because you can see what else a change or outage will affect. A CMDB overlaps with an asset register but is not the same: the register is geared toward ownership, cost, and depreciation, while a CMDB is geared toward service context and dependencies. Smaller organisations often start with a solid asset register and add CMDB-style relationships only as their environment grows complex.