The advantages of electricity as compared to other forms of energy is as follows:

(i) Electricity can be readily transmitted over large distances with relatively small loss in energy.
(ii) Electricity can be easily converted to other forms of energy ike heat, light, sound, motion, etc.
(iii) electricity is the most convenient source of energy.

Electricity playing an important role in modern society has a wide range of applications:

(i) Electricity is used in heating, lighting, cooking, operating fans, geysers, etc. in our houses, hospitals, hotels, office buildings, food storage plants.

(ii) Electricity is used in industries to run various types of machines.

(iii) In transportation to pull electric trains, trams, etc. 

(iv) Electricity is used for irrigation purposes in agriculture.

The materials can be broadly classified into two categories namely:

(i) Conductors: Conductors are the substances through which electric charges can flow easily.

For example, the electrons of the outer shells of metallic atoms are loosely bound to the nucleus. These electrons are quite free to move. Hence, metals have high electrical conductivity.

(ii) Insulators: The substances through which electrical charges cannot move freely are known as insulators.

In insulators, the electrons are tightly bound to the nucleus and cannot move away from it. Since, the electric charges are unable to move freely in insulators, they are poor conductor of electricity. 

Table: Examples of Conductors and Insulators: