1. A subset of the value domain of a variable within a component or system in which all values are expected to be treated the same based on the specification. [Reference: After ISO 29119]
2. subset of the range of values of a variable, or set of variables, within a test item or at its interfaces such that all the values
in the partition can reasonably be expected to be treated similarly by the test item (i.e. they may be considered "equivalent") by the test item
