A computer appliance is any type of hardware device that can be connected to a computer with the use of some type of cable, and which is designed to perform specific tasks. As with most types of appliances, these devices are self-contained and not intended for upgrading or repairs by the end user. In order to function properly, the appliance must have a connection to a power source as well as to the hard drive of the computer system. Once those connections are made, the computer appliance can be used to carry out whatever task or tasks it was designed to perform.
One common example of a computer appliance is an external hard drive. This particular device provides resources that make it possible to manage software applications that would not be capable of running on the internal hard drive of the computer itself. Users with older systems who want to augment capacity rather than buying a new system will often find this type of computer appliance makes it possible to enjoy the use of newer programs without the need to upgrade the basic system.
Another common example of a computer appliance is the simple computer printer. Usually powered by connecting the device to a wall outlet and using a USB cable to connect the printer to the computer hard drive, the printer is able to receive data from the system and print various types of documents. Software is normally required to ensure that the printer is recognized by the computer or the network that the computer is connected with in order to manage print jobs.
Scanners are another type of computer appliance that makes it possible to scan documents and create images that are then transmitted and stored on the hard drive. Typically, software is required to allow the hard drive to recognize the scanner and make sure the images are saved in a format that can be easily read by other programs residing on the hard drive. There are even fax machines that can be directly connected to a hard drive and used to send and receive documents with ease.
While a computer appliance once required some sort of cable to connect to a computer hard drive, that is no longer the case. Many designs today allow for the use of wireless connectivity to the computer, although most will still require a wired connection to some sort of power source or at least the use of an internal battery that must be charged from time to time. A range of appliances can be purchased at just about any retailer that offers desktop and laptop systems.