Insulators are devices that are installed between conductors at different potential levels or between conductors and grounding structures, capable of withstanding voltage and mechanical stress. There is a wide variety of insulators, with varying shapes. While the structures and appearances of different types of insulators differ significantly, they are both composed of two main parts: the insulating component and the connecting hardware.

Insulators are specialized insulation components that play a crucial role in overhead transmission lines. In the early years, insulators were commonly used on utility poles. Gradually, as high-voltage transmission towers were developed, many disc-shaped insulators were hung at one end. These are intended to increase the creepage distance, and they are typically made of glass or ceramic, hence the name insulators. Insulators should not fail due to various mechanical and electrical stresses caused by changes in environmental and electrical load conditions. Otherwise, the insulators would not serve their critical function, and this could damage the entire line's usability and service life.