Relays are a type of switching device that are often found in countless electrical assemblies, allowing for multiple circuits to be controlled with ease. Relays may come in a number of types and forms to accommodate particular applications and needs, and solid state relays (SSR) are a particular variation that utilizes semiconductors to switch high voltage circuits. Finding use for the management of AC power, motor speed control, power switching, and much more, it can be useful to have a general understanding of how such relays operate, as well as the different subtypes that are available.