Cussler Paul

What is the difference between an author writing with and an author and some other author?

I am reading a Clive Cussler book and it is written by Clive with Paul K., he also has some books that are by Clive and Dirk C. I don’t know what each means.
I would like to know the difference between the “and” and the “with”.

The first was written by Clive Cussler and Paul K, and the second one was written by Clive Cussler and Dirk Cussler, probably his brother.

White Death Alternate Ending (Part I)