The operator defines how to compare values in a test. For example, you can use an equality operator to test whether the salaries in two columns are the same.
For a table pair, the operator defines how to compare each value in Field A with the corresponding value for Field B. For a single-table constraint, the operator defines how to compare the each value in the field with the constraint value.
The operators that you can choose vary based on the type of test and whether the test is for a table pair or single table. An error appears when you try to create a test that contains an operator that is not supported.