Insulators are devices installed between conductors at different potentials or between conductors and grounding components, capable of withstanding voltage and mechanical stress. There are many types of insulators, each with different shapes. Although the structures and appearances of different types of insulators vary significantly, they are both 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, and gradually evolved to include many disk-shaped insulators hanging at one end of tall, high-voltage transmission towers. These are designed 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 serve their significant purpose and could damage the entire line's usage and operational lifespan.