A material that current does not easily flow through is called an insulator.

Here are some examples of insulators:

* Rubber

* Glass

* Plastic

* Wood

* Air

* Diamond

Insulators have a very high electrical resistance, meaning they resist the flow of electrical current. This is because their electrons are tightly bound to their atoms and cannot move freely.

In contrast, materials that allow current to flow easily are called conductors. Examples include:

* Copper

* Silver

* Gold

* Aluminum

* Water (with impurities)

Let me know if you have any other questions!