I am having issues with certain concepts regarding Wordpress and it's development, if anyone could clarify things for me that would be great!

I have an understanding of PHP classes and an understanding of how to generate and work with Wordpress Custom Post Types, are CPT's objects of a class i.e. is there a 'Post' object and custom post types are just objects of the class?

The reason I ask is; if I create a new Custom Post Type and use functions such as get_the_author() on my custom post type then the functions work, although I haven't necessarily defined the author while setting the CPT up.

I am presuming that this is because it is of the post object and the author is a property set by a setter when ANY post type is created? but this is where my understanding falls down a little.