What is a set of values?

A Value Set in the context of testing is a fixed, defined, or limited set of values that a variable, parameter, or data field can take. It is used to restrict possible input data and ensure their correctness.

Examples:

• Gender: Male, Female, Not specified.
• Order status: Created, Processing, Shipped, Delivered, Canceled.
• Operating mode: Online, Offline.

Using value sets simplifies testing boundary conditions and equivalence classes, as it allows focusing on verifying each permissible value of the set (and sometimes impermissible ones if the set is closed).