Why use int in enum declaration?

Question

What's the point of using : int in the enum declaration as following?

public enum AAType : int
{
    Folder = 0,    
    File = 1,   
    Link = 2
}

Answer 1

The default underlying type of an enum is int, so by specifying it explicitly you only (perhaps) gain in clarity, but the behavior's just the same as if : int was omitted.

Answer 2

The default backing type of enum is int. You can change the backing type to something else, like short or long. Specifying int is probably just for clarity.

Answer 3

The fact that an Enum is a specialized Int you can use bytes for each Enum value (Apple = 1, Pear = 2, Orange = 4) and then you can pass the Enums in Piped and determine what to do based on the byte value (look at Reflection.BindingFlags, etc).