OMGWTF CLASSES?!

Ok, so i've been reading alot lately, maybe too much, but I can always go back and re-read some things. Latest topic, Classes. This is my basic understanding of classes. Please tell me if i'm right or wrong.

I'll use cin as my example, i.e. cin.get(), cin.ignore(), etc.

cin is a structure , inside of the class Iostream. It's a structure, in the sense that there's multiple instances of cin (see above for reference to this.) So, iostream is the class, cin is a structure inside of it which contains all of the console input functions you need.

Since we use cin, it's function prototypes would be in the public section of the Iostream class, where it's actual implementation would be somewhere in the cin structure. Say we are implementing cin.ignore, in the iostream header it would look like this, right?

[PHP]iostream.cin::ignore[/PHP]

then a definition of what cin.ignore is. Correct?