A servo motor is an electrical device which can push or rotate an object with great precision. If you want to rotate and object at some specific angles or distance, then you use servo motor. It is just made up of simple motor which run through servo mechanism.
How Servo Motors Work
Arduino uno control servo with photoresistor -Wiring, code, video
What is a Servo Motor and How it Works? - RealPars
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Servo Motor - Types and Working Principle Motor, Electronics circuit, Tracking system
Sevo motors - Remote Control Toys & Vehicles
Servo Motor Basics And Working Principle
Praktikum Motor Servo
Servomechanism, Theory and Working Principle of Servo Motor