Difference between abridged and unabridged audiobook in iOS Books app

By definition the unabridged is simply a narrator reading the novel word for word as written.

An abridge novel may have more of a script approach and separate characterisation; as it were, be more of a play or theatre.

Sections of the novel used to describe scenery place and time may have been completely discarded; even timelines of the novel could have been moved to add clarity, definition or other effect.

Abridged should not necessarily be accorded with condensed length by the listener.

From a point of audibility, narrative and understanding the two should be considered more differing experiences.

Also if you are using the novel for language learning or enhancement listening to both and the nuances implied may be somewhat advantageous to you .

Literature is so appealing, the life blood of empathy and compassion right at the very centre of the human condition.

You probably need to ask the publisher.