Learn in the textbookActuators and Device Control
DefinitionAn actuator (アクチュエーター) is the umbrella term for output-side devices that take a control signal from a computer and turn it into physical motion, such as rotating or extending and retracting.
ExplanationA sensor (センサー) on the input side measures physical quantities such as temperature or brightness and turns them into electrical signals, while an actuator sits at the end of the signal flow and moves real objects. In an IoT system, it handles the part that does the work on site, for example opening and closing a sprinkler valve based on a reading.
AnalogyIf sensors are the eyes and ears, actuators are the hands and feet that actually move on the brain's orders.
Memory hookThe word is built on act (to move or do), so read it as "the thing that makes something act."