You can check out the video explaining Snoke’s connections to Darth Vader and Emperor Palpatine below, courtesy of Star Wars Explained YouTube channel.
Now, this points out another fan theory that suggests that Snoke is Darth Plagueis, the midi-chlorian manipulator Dark Lord Sith, who trained Darth Sidious.
There are major SPOILERS for The Last Jedi ahead, read on at your own risk.
Before The Last Jedi came out, many believed that the ring on Snoke’s finger had a Kyber crystal on it, but that is not the case as the Visual Dictionary points out.