When a conductor is introduced into an electrostatic field, a redistribution of charges begins in the conductor, which leads to the equalization of potentials of all points of the conductor. Because any value of the potential can be taken as zero, then it is considered that inside the conductor the potential of all points is zero.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.