virtual appliance - Computer Definition
(1) The correct meaning of virtual appliance is definition #2 below; however, the term may be used to contrast a software alternative to hardware (see hardware appliance).
(2) An operating system and application packaged together as a pre-installed system image for a virtualized environment such as VMware or Xen. Faster and Simpler The regular process of deploying a new application in a virtualized computer is to set up a new virtual machine partition, install the operating system and then install the application. The installation processes are time consuming and configuration mistakes can be made. In contrast, virtual appliance deployment is faster. The appliance image (OS and application) is copied to the virtual machine pre-installed and pre-configured. There is no tedious installation, and since the OS and application have already been tested together, the operation of the programs is less error prone. See virtual machine, virtualization, software appliance and system image.