What does the "final published version" refer to in copyright?
The usual workflow with Springer is:


You prepare your paper, and submit it as a PDF file to the conference.
The conference reviews the paper, and you get the acceptance notification + conference reviews back.
You revise your paper, and submit the source code to Springer.
Springer does copyediting, and you get the page proofs back.
You check the page proofs and submit your corrections to Springer.
Springer prepares the final PDF and posts it on their web page.


(Note that steps 1–3 involve work from you + research community. Steps 4–6 involve some added value from the publisher.)

The "author-created version" refers to your output after step 1 or 3. This is what you can self-archive.

The "final published version" refers to Springer's output after step 6. This is a version you cannot self-archive.

(IANAL, etc.)