An insulator has a higher resistance compared to a conductor.
Conductors, such as metals (like copper or aluminum), have low resistance and allow electric current to flow easily through them. This is due to the presence of free electrons that can move freely in the material.
In contrast, insulators (such as rubber, glass, or plastic) have very high resistance, which significantly restricts the flow of electric current. Insulators lack free charge carriers, making it difficult for electricity to flow through them.
Thus, insulators are used to prevent the flow of electric current, while conductors are used to facilitate it.