Your class can have built-in types as data members, or custom types. These data members can be declared in the class (and created when an instance of the class is constructed), or they can be pointers to objects created in the free store or references to objects created elsewhere. Bear in mind that if you have a pointer to an item created in the free store, you need to know whose responsibility it is to deallocate the memory that the pointer points to. If you have a reference (or pointer) to an object created on a stack frame somewhere, you need to make sure that the objects of your class do not live longer than that stack frame.
When you declare data members as public it means that external code can read and write to ...
