Test Data can refer to the inputs for a program, which might also include any configuration/setup data, but also the data outputs which might require further analysis to detect issues.
From Wikipedia: "Some data may be used in a confirmatory way, typically to verify that a given set of input to a given function produces some expected result. Other data may be used in order to challenge the ability of the program to respond to unusual, extreme, exceptional, or unexpected input.
The ways / approaches of Test Data production:
Test data may be produced in a focused or systematic way (as is typically the case in domain testing), or by using other, less-focused approaches (as is typically the case in high-volume randomized automated tests).
Test data may be produced by the tester, or by a program or function that aids the tester.
Test data may be recorded for re-use, or used once and then forgotten.
Domain testing is a family of test techniques that focus on the test data. This might include identifying common or critical inputs, representatives of a particular equivalence class model, values that might appear at the boundaries between one equivalence class and another, outrageous values that should be rejected by the program, combinations of inputs, or inputs that might drive the product towards a particular set of outputs."