What is an Encoder?

How does an encoder work?Encoders may produce either incremental or absolute signals YUMO Automation | Sales representative of Encoders, Sensors, Programmable Logic Controllers, Human Machine Interfacte, Slip rings, Couplings Encoders use different types of technologies to create a signal, including

How to ensure the accuracy of rotation position of servo motor? All this is due to a kind of artifact, encoder. But what is encoder? How can it accurately measure the position of the motor?