Minifundio is a very small agricultural property that makes its exploitation difficult. More than with the concept of plot (agricultural land within a boundary) or with that of agricultural property (all plots belonging to the same owner), it is related to that of agricultural exploitation (plots exploited by the same person responsible for management, whether or not he is the owner). The minimum extension of a farm to allow adequate management is different depending on the quality of the land "Land (economy)"), the crop, the work "Labor (economy)"), the capital "Capital (economy)") and the techniques used, and the geographical space in which it is located. In Spain, the figure of 10 hectares is usually used, which can be an indicative figure for a dryland cereal farm in the Central Plateau to be considered small; but it would not be for a Valencian orchard, which with that size is perfectly profitable (a farm of more than 100 hectares would be considered a large estate, with the rest being an average farm).[1]​ In other areas of the world or for other sources, the figure may be different: in America or Australia, especially in sparsely populated areas with a greater tendency towards extensive agriculture and livestock, the figure of 30 hectares can be used; In Southeast Asia, with a tradition of intensive agriculture (such as heavily irrigated rice farming in overpopulated areas), the figure of 2 ha can be used.[2]​.

A smallholding has, by definition, such small dimensions that it prevents the farmer from obtaining sufficient production to be marketed or obtaining sufficient monetary income, forcing self-sufficiency and subsistence agriculture. Although it usually coincides with it, the minifundio is not strictly synonymous with the concept of small property, since an agricultural holding could be made up of several small properties until it reaches a sufficient size. Even more common is that a large property is rented in small plots to many individual farmers, whose farms, not large enough for effective management, are true smallholdings.

The smallholding can be formed in inheritance regimes "Inheritance (right)") in which the testator divides his property equally among his heirs, thus resulting in progressively smaller pieces of land. The successive partitioning of the inherited land over time can lead to extreme cases in which a landscape of longueras dominates ("[4]​ of very low profitability. The minifundio is generally presented in contrast to the latifundios in traditional economies", technologically backward and with little capital investment"). The smallholder peasants live very close to the survival level, and when they are forced to distribute the scarce land among their descendants, the problem of small size of the plots. When even this is not possible (for example, when inheritance customs protect the unity of inheritance in the eldest son) and there is strong demographic pressure, the historical conditions arise for rural exodus, which, for opposite reasons, also occurs with other exploitation structures, such as latifundism.