Zero population growth (ZPG) is a demographic state where a population's size remains stable with no net increase or decrease over time, achieved when the number of births plus the number of immigrants entering the population is exactly equal to the number of deaths plus the number of emigrants leaving the population. In other words, the rate of natural increase (births minus deaths) is offset by the rate of net migration (immigrants minus emigrants), resulting in an overall population growth rate of zero. Achieving ZPG can have various implications for a society, such as a more balanced age structure and potentially reduced pressure on natural resources and the environment, but it can also present challenges related to an aging workforce and potential economic impacts.