Definition - What does Virtual Appliance mean?
A virtual appliance is a software application residing and operating in a preconfigured virtual environment or platform. Virtual appliances are accessed remotely by users and do not require locally-installed hardware.
Techopedia explains Virtual Appliance
Applications of all sizes and complexity can be hosted through remote infrastructures. Virtual machines mirror typically installed computer OSs, but do not contain software applications. In other words, a virtual appliance is essentially a software appliance that is installed on a virtual machine.
Virtual appliances have several benefits, particularly ease of deployment. Users are not responsible for managing hardware and software compatibility or OS considerations such as integration and isolation in the event of a system crash. Virtual appliances play a significant role in cloud computing’s software as a service (SaaS) model where remote software access is delivered through a Web browser.