Theory:

Based on the property of conductance of electricity, substances are classified into two types:
  • Conductors
  • Insulators (or) bad conductors of electricity
The electrons of different atoms have different degrees of freedom to move around. In some materials, such as metals, the outermost electrons in the atoms are loosely bound, and they move randomly whereas in some materials, they are bounded tightly

Let's imagine a metal wire connected across a battery. When a voltage is given across the ends of the metal wire, the free electrons drift in one direction. So, a really good conductor has lots of free charges while those who don’t have enough free charges would not be good at conducting electricity or say that they would be poor conductors of electricity.
  
Conductors:

In an electrical circuit, the conducting wire, which is made up of metal, allows current to pass through them. Such types of materials are called conductors.
  • Conductors are the materials whose atoms have electrons that are loosely bound and are free to move throughout the material.
  • A good conductor offers very little resistance to the flow of charge on external voltage. This flow of charge (electron) constitutes an electric current.
  • A good conductor has high electrical conductivity.
7 (2).svg
Conductor with least resistance
The materials which allows the electric current to pass through them are called conductors.
Example:
Human bodies, tap water, safety pins, coins and needles.
copper-72062_1280.jpg
Copper wires
safety-pin-3362535_1920.png
Safety pins
All metals are good conductors of electricity. Graphite, a non-metal used in pencil lead, is also a conductor of electricity.
 
iron-rods-474810_1920 (1).jpg
Iron rods
 
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Metal gate

Insulators
  • In an electrical circuit, if we use Cotton thread instead of Copper wire, the current will not flow through the circuit. This situation is because cotton is a poor conductor of electricity, and it does not allow current to pass through it. Such types of materials are called insulators.
  • The materials that donot have enough free electrons are not good at conducting electricity. We can say that they would be poor conductors of electricity and are called insulators.
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High resistance to the flow of electron
The materials that do not allow the electric current to pass through them are called insulators.
Example:
Rubber bands, plastic materials, rubber, wood, glass, air and pure water.
Example:

wood-1868104_1920.jpg
Reference:
https://pixabay.com/photos/copper-wire-cable-scrap-metal-72062/
https://pixabay.com/photos/safety-pin-handicraft-sewing-3362535/
https://pixabay.com/photos/iron-rods-reinforcing-bars-474810/
https://pixabay.com/photos/car-tyres-wheel-band-car-63928/
https://pixabay.com/photos/wood-pile-logs-bole-firewood-1868104/
https://pixabay.com/photos/gateway-forged-entrance-gate-3130595/