What is is an insulator?

Answer 1

An insulator is something that inhibits the movement of energy such as heat, sound, and light.

In electrical usage, an insulator is a coating or material that prevents discharge from an electrical wire or system.

In general terms, it means a barrier to something, such as heat, electricity or between people.

Answer 2

The term thermal insulation can refer to materials used to reduce the rate of heat transfer, or the methods and processes used to reduce heat transfer.=Heat energy can be transferred by conduction, convection, radiation or when undergoing a phase change. For the purposes of this discussion only the first three mechanisms need to be considered.==The flow of heat can be delayed by addressing one or more of these mechanisms and is dependent on the physical properties of the material employed to do this.==- Shruti=