Insulators are devices installed between conductors at different potentials or between conductors and grounding components, capable of withstanding the effects of voltage and mechanical stresses. There is a wide variety of insulators, each with its own unique shape. Although different types of insulators have considerable differences in structure and appearance, they are all composed of two main parts: the insulating component and the connecting hardware.

Insulators are specialized insulating devices that play a crucial role in overhead transmission lines. In earlier years, insulators were commonly used on utility poles. Over time, many disk-shaped insulators were hung at one end of tall, high-voltage transmission towers to increase the creepage distance. Typically made of glass or ceramic, these are referred to as insulators.