An electronic keyboard or digital keyboard is a type of keyboard instrument. Its sound is generated or amplified by one or more electronic devices. Modern usage of the term "electronic keyboard" typically describes a type of inexpensive sampler marketed to amateurs and children. The term is occasionally used as an umbrella descriptor for any electronic musical instruments with a musical keyboard (including but not limited to electric pianos, digital pianos, synthesizers, mellotrons, samplers, electronic organs, and arranger keyboards) but professional musicians generally refer to these instruments by name or simply as "keyboards", reserving the term "electronic keyboard" for the inexpensive type noted above.