Optical sensors are sensors whose emitting and receiving elements are placed next to each other in the same optical assembly. The rays emitted by the transmitter are reflected from the surface of the detected object and return to the receiving element. An optical sensor is a device that converts light rays into electronic signals. Typically, an optical sensor is part of a larger system that integrates a measuring device, a light source, and the sensor itself. This is usually associated with an electrical trigger, which responds to a change in signal within the light sensor. One of the characteristics of an optical sensor is its ability to measure changes in one or more light beams. This change is usually based on changes in light intensity. When a phase change occurs, the light sensor acts as a photoelectric trigger, increasing or decreasing the electrical output, depending on the type of sensor. Optical sensors, types and characteristics are described in detail in this final paper.