Let us consider a neutral sphere made with metal. Since metal is a good conductor of electricity, so we have chosen the object made from metal. The neutral sphere is placed on an insulator sheet, as shown in the diagram (right) so that the charge doesn’t flow out from the system. As we can see in figure 2, there is an equal amount of positive and negative charge on the sphere (number of positive charge = 6 = number of negative charge), and hence, we can say that the object is neutral as shown in the first part of the diagram.

In the second part of the diagram, we bring the negatively charged rod (rod shown in figure 3 & 4 having negative charge) near the sphere. Sphere has both positive and negative charge, and as the rod is brought near to the sphere, the negative charge in the sphere is repelled by the rod (due to the same charge) and move to the outer side of the sphere. The numbers of positive charges are equal to the number of negative charges. We can say that the total charge on a system is zero.

In the third part of the diagram, we ground the sphere, and the negative charge moves to the ground.  So only positive charge remains left. In the fourth part of the diagram, the positive charge evenly spread on the sphere.

Note: In Charge by Induction method, objects are not in physical contact with each other while in the remaining two methods, objects are in physical contact with each other.