Conductors A material or an object that conducts heat, electricity, light, or sound. Electrical conductors contain electric charges (usually electrons) that are relatively free to move through the material; a voltage applied across the conductor therefore creates an electric current. Insulators (electrical nonconductors) contain no charges that move when subject to a voltage.
Insulators A material that does not easily transmit energy, such as electric current or heat. Materials such as wood, plastic, and ceramics are insulators. Fiberglass is an example of a heat insulator.
***I just copied and pasted from dictionary.com. I think these are good examples/definitions of what they are. Hopefully this helped.
In conductors electric charges are free to move from place to place while in insulators electric charges are fixed in one place and cannot move from place to place.
Conductors conduct electricity ,with the help of the free electrons present in there atom , insulators have no free electrons so they wont conduct electricity , so insulators are used to cover the conductors , due to safety reasons
Substance having large conductivity and negligible resistivity are called conductors for example, gold, silver, copper etc. A conductor has a very large conduction band. The valence band in conductors is very small empty band. Forbidden energy band does not exist in conductors. The valence band and conduction band overlap each other. On the average there are 1023 free electrons per centimeter cube in conductors.
The substances having negligible conductivity and large resistivity are called insulators for example paper, plastic, wood etc. The conduction band is very small. This is because of negligible conductivity. It has very large valence band. Forbidden gap has a large value of energy. That is why some of the insulators burn on heating but do not conduct electricity. There is only one free electron per centimeter cube in an insulator.
The substances through which electricity can pass are known as conductors. The substances through which electricity cannot pass are known as insulators. There are no free electrons and ions present in the insulator, so they do not conduct electricity. According to energy band theory in conductors the valence band and conductor band are overlapped, so electrons from valence shell easily jump to conductance shell. In this way conductors conduct electricity. In insulators there is a large forbidden band present between valence band and conduction band, so insulators do not conduct electricity.
The Difference between conductors and insulators is that conductors conduct electricity and insulators does not.On the basis of energy band theory conductors have partially filled valence band and insulators has fully filled valence band.
In case of conductor, conduction band and valence band are overlapping, n therefore electrons are very free to move. But in Semiconductors there is a bit distance between the their valence band and conduction band. When there are heated electron jump to the conduction band from the valence band but in case of Insulators there is a big distance between the conduction band and valnce band so electron can not move from valence band to the conduction band. So that's y conductors are liable to conduct electricity and the semiconductors are intermediate but Insulator do not allow electricity pass through them.
