Computer appliance

The hardware and software are delivered as an integrated product and may even be pre-configured before delivery to a customer, to provide a turn-key solution for a particular application.

Traditionally, software applications run on top of a general-purpose operating system, which uses the hardware resources of the computer (primarily memory, disk storage, processing power, and networking bandwidth) to meet the computing needs of the user.

By tightly constraining the variations of the hardware and software, the appliance becomes easily deployable, and can be used without nearly as wide (or deep) IT knowledge.

Additionally, when problems and errors appear, the supporting staff very rarely needs to explore them deeply to understand the matter thoroughly.

This prevents customers from needing to perform complex integration work, and dramatically simplifies troubleshooting.

In fact, this "turnkey operation" characteristic is the driving benefit that customers seek when purchasing appliances.

Some computer appliances use solid state storage, while others use a hard drive to load an operating system.

Cobalt Qube 3 - a computer server appliance (2002, discontinued)
A Niksun network security appliance, being used by the U.S. Army (2016)
A Linksys wireless router sitting atop a Comcast cable modem in a home setting (2006)
The back of a Siemens programmable logic controller (2013)