Appliance may refer to a device with a narrow function:

• Home appliance, household machines, using electricity or some other energy input.
• Small appliances
• Major appliances
• In medicine and dentistry, custom-fitted appliances to an individual for the purpose of correction of a physical or dental problem such as prosthetic, orthotic appliances, and dental braces.
• Computer appliance, a computing device with a specific function and limited configuration ability
• Fire apparatus, a fire engine or fire truck in British English