Final answer:
An insulator is a material that resists the flow of electrons due to high resistance, as opposed to a conductor which allows electrons to move freely. Insulators have electrons bound tightly to atoms, making them poor conductors of electricity, while conductors and semiconductors are utilized in electronics for their varying conductivity.
Step-by-step explanation:
A material that resists the flow of electrons is called an insulator. Insulators have a high resistance to electron flow, meaning they do not allow electric charge to move freely through them. This is because the electrons in insulators are usually tightly bound to atoms and are not free to move around. Examples of insulators include materials like plastic, glass, and rubber.
The opposite of an insulator is a conductor, which allows charge to move with relative ease due to the presence of free electrons. Conductors like copper, gold, and silver have low resistance, which makes them ideal for use in electronic circuits and electrical wiring. Some materials, known as semiconductors, have properties between those of insulators and conductors and their ability to conduct electricity can be greatly affected by the presence of impurities, which is essential for modern electronics.