What is the enum module and when should you use it?

Question presented to candidate: "What does Python's enum module give you over plain constants like PENDING = 1, and how do Enum, IntEnum, StrEnum and Flag differ? When would you use one?"

What a strong answer should cover:

• An Enum is a class whose members are a fixed set of named singleton objects with a .name and a .value; members cannot be reassigned, iterate in definition order, and are looked up with Status(2) or Status["SHIPPED"]
• Why it beats magic strings and module constants: typos fail loudly with AttributeError, readable repr, type checkers can verify exhaustive match, and members carry methods and properties
• Plain Enum members are not equal to their values (Status.SHIPPED == 2 is False); IntEnum and StrEnum (3.11) are subclasses of int/str, which helps interop (JSON, databases) but loses type safety
• auto(), aliases (two names with one value) versus @unique / @verify(UNIQUE), and Flag / IntFlag for combinable bit flags with | and in
• Version details: enum arrived in 3.4 (PEP 435), auto and Flag in 3.6, StrEnum, ReprEnum and verify in 3.11, which also changed format() of str/int mixins; 1 in Status raises TypeError on 3.11 but returns True/False on 3.12+
• When not to: open-ended or user-defined sets of values, or values loaded at runtime

Code / implementation expected: Optional — define an order-status enum, look members up from external values, and use it in match.