This section compares classes and structures:

• Inheritance enables one class to inherit the characteristics of another
• Type casting enables us to check and interpret the type of a class instance at runtime
• De-initializers enable an instance of a class to free any resources it has assigned
• Reference Counting allows more than one reference to a class instance
• Structures are value types so they are always copied when they are passed around in code
• Structures do not use Reference Counting
• Classes are reference types