Insulators are devices installed between conductors at different voltages or between conductors and grounding components, capable of withstanding voltage and mechanical stress. There are numerous types of insulators, each with varying shapes. Although 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 controls that play a crucial role in overhead transmission lines. In the early years, insulators were commonly used on utility poles, gradually evolving to the point where many disc-shaped insulators were hung at the top of tall, high-voltage transmission tower connections. These are designed to increase the creepage distance, and are typically made of glass or ceramic, hence the name "insulator." Insulators should not fail due to various mechanical and electrical stresses caused by changes in environmental and electrical load conditions; otherwise, they would not fulfill their significant function, potentially damaging the entire line's usability and operational lifespan.