WMI is an acronym for Windows Management Instrumentation. WMI is the Microsofts implementation of Web-Based Enterprise Management (WBEM) - a new management technology that allows software to monitor and control managed resources throughout the network. Such managed resources include hard drives, file systems, settings of operating system, processes, services, shares, registry settings, networking components, event logs, users, groups, etc. WMI allows monitoring of performance counters as well. Microsoft applications such as Exchange and SQL Server have WMI built-in. Many non-Microsoft applications utilize WMI and thus they could be monitored using Advanced Host Monitor as well.