The introduction of Supreme Leader Snoke in Star Wars: The Force Awakens generated a lot of speculation among fans, and the hope was that The Last Jedi would shed some light on his identity. Instead, Rian Johnson decided to kill him off and have Kylo Ren appoint himself the new "Supreme Leader" of the First Order.
The Rise of Skywalker would later address Snoke's origin story in a throwaway scene showing clones of the villain in a vat, and by revealing it was Emperor Palpatine pulling his strings.
Now, though, and a new Star Wars book may have shed a little more light on Snoke's background.
As you can see below, it's mentioned that he's "an artificial genetic construct concocted by the resurrected Darth Sidious to be his proxy in power. Snoke has free will, but his actions and goals are still orchestrated by Sidious." So, he clearly wasn't just a puppet, but did report to Emperor Palpatine. The Sith Lord clearly felt he needed a proxy that the First Order could rally around in his absence.
This does seem to contradict previous information about Palpatine sensing Snoke's presence, though it's possible the Emperor killed the original and made one who would serve him.
None of it really makes sense, though, and it's frustrating this is being addressed in books rather than the movies themselves. Then again, it's not like the original trilogy revealed Palpatine's past!
Check out this new intel below: