In business and economics, a restriction is a type of boundary or regulation placed on the trade of certain goods or services.

In general usage, a restriction is a specific type of rule which defines a finite (and generally absolute) boundary defined for a type of process or function.

In mathematics, in the context of sheaves, a restriction is a type of function.

In statistics and econometrics, and most commonly in regression analysis, a restriction is a condition on the variables.

in biology, it corresponds to the restriction of the rule of sensibility of bacteria to phages, and therefore corresponds to the means by which the resistance phenomenon occurs : the restriction enzymes.

The adjectival form, "restricted," may be used in reference to written or unwritten covenants enforcing racial or ethnic segregation or religious segregation — frequently anti-Jewish or more generally anti-Semitic — in housing (see "Restrictive covenant") or in organizations, such as country clubs.