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 are many types of insulators, each with varying shapes. While the structures and appearances of different types of insulators may differ significantly, they are both primarily composed of insulating parts 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. Over time, they evolved to include many disk-shaped insulators mounted at the top 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.