This rule uses WMI to discover all Windows logical disks excluding removable drives and network drives. This rule does not discover drives mounted with no drive letter. There is a separate discovery rule for such drives.
Knowledge Base article:
Summary
This Discovery Rule discovers and populates the Windows Server Class named “Windows Server 2012 Logical Disk" with instances of Logical Disks (for example C:, D:) that are discovered on Windows Server 2012. Please note that only Local Disks are detected. Logical Disks that are classified as Removable, Compact Disk, Network Drive, and RAM Disks are excluded.