C#.NET enum category: is an enum a value type or a reference type?

Introduction / Context:
Understanding whether an enum is a value type or a reference type is fundamental to memory layout, assignment semantics, and performance in .NET.

Given Data / Assumptions:

• You are classifying enums in C#.
• No unusual runtime features change the core type system.

Concept / Approach:
In .NET, every enum type inherits from System.Enum, which inherits from System.ValueType. Therefore, all enums are value types. Value types are typically stored inline (e.g., on the stack or inside containing objects) and copied by value semantics.

Step-by-Step Reasoning:

Verification / Alternative check:
Reflect any enum in code and inspect typeof(MyEnum).IsValueType which returns true. IL disassembly also shows the inheritance tree.

Why Other Options Are Wrong:
Reference type is incorrect; enums are not classes. Size or project settings do not alter type category, and you cannot programmatically switch a type from value to reference.

Common Pitfalls:
Confusing enums with classes or assuming large enums might be treated as references. The category is fixed by the CLR type system.

Final Answer:
enum is a value type.