Physical Science:

On the basis of electrical behavior there are four types of materials exist in nature; they are conductor, insulator, semiconductors, and superconductors.

Conductor: It is a material where charge carriers (electrons or ions) are free to move within it. Copper, aluminum, gold, mercury, iron, water-salt solution, etc. are a few examples of conductors. In a conductor, the outermost electrons of an atom are loosely bounded with its nucleus and hence are free to move throughout the material even at very low temperature. The random motion of electrons causes zero net electric current in a conductor unless an external electric field is applied on it. Insulator: It is a material where electrons are tightly bounded with their atom and can not move very easily. Plastics, glass, rubber, wood, porcelain, etc. are few examples of insulators. Check the simulation link conductor & insulator

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javalab.org/en/electric_current_en/

Semiconductor: It is a material having properties between insulator and conductor. Silicon and germanium are good example of it. At low temperature this material behaves as an insulator and at high temperature it behaves as a conductor. The conductivity of a semiconductor can be increased enormously by doping of this material with a very small amount of suitable dopants such as boron, phosphorous, or arsenic. Superconductor: It is a material which transfers electrons from one atom to another throughout the material without any resistance. No loss of energy can be observed when the material conducts electricity. Mercury shows superconducting nature at temperature below 4 Kelvin.