An optoisolator, also known as an optocoupler, is an electronic component that transfers electrical signals using light waves to provide electrical isolation between its input and output. This isolation helps protect sensitive components from high voltages or noise in a circuit, making it essential in various applications, such as in power supplies and signal processing. The basic structure of an optoisolator includes a light-emitting diode (LED) and a photodetector, such as a photodiode or phototransistor. When an electrical signal activates the LED, it emits light that the photodetector receives, allowing the signal to pass through without direct electrical connection.