Virtual machine configuration is the arrangement of resources assigned to a virtual machine. The resources allocated to a virtual machine (VM) typically include allocated processors, memory, disks, network adapters and the user interface. Configuration refers to both the specific elements included and the way those elements are set up.
Virtual machines can be created quickly and easily but the default configuration settings may not be the best ones for VM performance. Each VM should be configured with only the resources it needs. For example, if a particular VM doesn't need a CD-ROM drive or a floppy drive, removing those items will improve VM functioning.