positioner vs rotary actuator

positioner and rotary actuator both are nouns.

Word	Noun	Adjective	Verb	Adverb
positioner	Yes	No	No	No
rotary actuator	Yes	No	No	No

As nouns, positioner and rotary actuator are synonyms defined as:

positioner and rotary actuator: (computer science) the actuator that moves a read/write head to the proper data track

positioner (noun)	rotary actuator (noun)
(computer science) the actuator that moves a read/write head to the proper data track	(computer science) the actuator that moves a read/write head to the proper data track
a device used to control the opening or closing of the actuator based on electric, or pneumatic signals.