Insulators are devices installed between conductors at different potentials or between conductors and grounding components, capable of withstanding voltage and mechanical stress. There is a wide variety of insulators, with diverse shapes. While the structures and appearances of different types of insulators may differ significantly, they are both primarily composed of insulating components and 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, and gradually, many disc-shaped insulators were hung at one end of tall high-voltage transmission line towers. These are intended to increase the creepage distance. Typically made of glass or ceramic, they are referred to as insulators. 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 and could damage the entire line's service and operational lifespan.