In the last chapter we looked at how you define .NET Framework classes. Classes are the most common of Framework types, and in many ways the most complex, but they’re not the only ones. In this chapter, we’ll look at the remaining types:
Structures, which are like baby classes,
Enumerations, which are simple lists of values, and
Interfaces, which are like the definition of a class without any implementation.
Like classes, structures, enumerations and interfaces are implemented using C# type and member keywords ...