A smallholding or smallholder is a small farm operating under a small-scale agriculture model. Definitions vary widely for what constitutes a smallholder or small-scale farm, including factors such as size, food production technique or technology, involvement of family in labor and economic impact. Smallholdings are usually farms supporting a single family with a mixture of cash crops and subsistence farming. As a country becomes more affluent, smallholdings may not be self-sufficient, but may be valued for the rural lifestyle. As the sustainable food and local food movements grow in affluent countries, some of these smallholdings are gaining increased economic viability. There are an estimated 500 million smallholder farms in developing countries of the world alone, supporting almost two billion people.