In principle, it is possible that particles in a system experience fluctuation in the direction of the external field at the moment of collision for a given temperature. If particles of a system fluctuate in the same direction as an external force at the moment of collision the second law of thermodynamic will be violated as the work that is done on the system is more than the energy that is applied to it. However, the particles obtain various microstates and fluctuate stochastically in different directions owing to random Browning motions. As a consequence, the probability of such an event in a real system with an order of Avogadro number of atoms is statistically almost zero. However, it is a significantly probable event in an extremely small microscopic system with a single atom for a small fraction of time -work can be done one kT more than applied energy. This is a considerable contribution to the work when kT is comparable to the amount of applied energy. The violation of the second law of thermodynamics is recognized for such a microscopic system when the system contains only a few degrees of freedom for the creation of statistically averaged entropy for each measurement. With a huge number of degrees of freedom in a real macroscopic system, statistically, the system dissipates energy in the form of heat, and entropy increases with time under an applied external field. As a result, it is understood that the behavior of a system is governed by the energy and entropy of that system and its surrounding. But how about the distribution of particles within the system without an external field in thermal equilibrium with a heat reservoir? How the configuration of particles in the system is characterized by the energy and entropy of the equilibrium system?