Poverty is the state of one who lacks a certain amount of material possessions or money. Absolute poverty or destitution refers to the one who lacks basic human needs, which commonly includes clean and fresh water, nutrition, health care, education, clothing and shelter. About 1.7 billion people are estimated to live in absolute poverty today. Relative poverty refers to lacking a usual or socially acceptable level of resources or income as compared with others within a society or country. For most of history poverty had been mostly accepted as inevitable as traditional modes of production were insufficient to give an entire population a comfortable standard of living. After the industrial revolution, mass production in factories made wealth increasingly more inexpensive and accessible. Of more importance is the modernization of agriculture, such as fertilizers, in order to provide enough yield to feed the population. People who practise asceticism intentionally live in poverty.