Now whenever a cavity is formed, there is the phenomenon, there will be interface between gas and the liquid, isn’t it? So, we will have surface tension. Now, what is surface tension? Surface tension is a force which is trying to keep the liquid surface. That means there is a force towards the liquid, say in the surface of water the molecules attract each other and the top molecules are attracted only by the bottom molecules because there is no molecule on top. So, there is a force towards the liquid. So, there will be a force towards the liquid. So, to the cavity to remain, the force required will be slightly more than just formation of the cavity itself. That means though we say this is the vapor pressure at which the water will cavitate, there is a possibility that due to surface tension the cavitation number, I have not defined Cavitation number, we will come to it just in a minute, that is the pressure perhaps should fall a little below. So, there is more force for formation of the cavity so that it can be retained. Are you understanding?