This is an old list of the WMI Win32_xxx classes and the description is missing, but you can imagin what it means out of the name. Hope it helps!
Thanks to Erhard Olszok aka GrayGhost for posting this list in another forum...
CIM_Chassis
CIM_VideoControllerResolution
Win32_1394Controller
Win32_BaseBoard
Win32_Battery
Win32_BIOS
Win32_BootConfiguration
Win32_Bus
Win32_CacheMemory
Win32_ComputerSystem
Win32_Desktop
Win32_DesktopMonitor
Win32_DeviceMemoryAddress
Win32_DiskPartition
Win32_DisplayConfiguration
Win32_DisplayControllerConfiguration
Win32_DMAChannel
Win32_Environment
Win32_Fan
Win32_FloppyController
Win32_Group
Win32_IDEController
Win32_InfraredDevice
Win32_IRQResource
Win32_LogicalDisk
Win32_LogicalMemoryConfiguration
Win32_MemoryArray
Win32_MemoryDevice
Win32_MotherboardDevice
Win32_NetworkAdapter
Win32_NetworkAdapterConfiguration
Win32_NetworkClient
Win32_NetworkConnection
Win32_NetworkProtocol
Win32_OnBoardDevice
Win32_OperatigSystem
Win32_PageFileSetting
Win32_PageFileUsage
Win32_ParallelPort
Win32_PCMCIAController
Win32_PhysicalMemory
Win32_PhysicalMemoryArray
Win32_PortResource
Win32_POTSModem
Win32_Printer
Win32_PrinterConfiguration
Win32_PrinterDriver
Win32_PrintJob
Win32_Process
Win32_Processor
Win32_Product
Win32_QuickFixEngineering
Win32_SCSIController
Win32_SerialPort
Win32_SerialPortConfiguration
Win32_Service
Win32_Share
Win32_SoundDevice
Win32_StartupCommand
Win32_SystemAccount
Win32_SystemDriver
Win32_SystemEnclosure
Win32_SystemSlot
Win32_TCPIPPrinterPort
Win32_Threat
Win32_USBController
Win32_USBHub
Win32_UserAccount
Win32_VideoController