Star Wars introduced viewers around the world to the concept of the Force and the light and dark sides of it, as well as to the Jedi and the Sith. Although there are many users of the Force on both sides, many have wondered why not all those on the dark side are Sith, as is the case of Kylo Ren and Snoke – here’s why. The Star Wars universe began back in 1977 with the film now known as Star Wars: A New Hope, which introduced the audience to a galaxy far, far away with a corrupt system. This film, along with the sequels Star Wars: The Empire Strikes Back and Star Wars: Return of the Jedi, form what’s known as the “original trilogy”.
The main villains in the trilogy were the Emperor and Darth Vader, both very powerful Sith lords. The backstory of Darth Vader was explored years later in the Star Wars prequels, which also featured other Sith apprentices, such as Darth Maul and Count Dooku. With the arrival of the sequel trilogy between 2015 and 2019 and the introduction of Kylo Ren and Supreme Leader Snoke, many fans began to wonder if they were also Sith, even if the remaining two had died in Return of the Jedi (though Palpatine ended up returning in Star Wars: The Rise of Skywalker), and with that came the big question of why not all dark side users are Sith.
First off, there’s a process to follow when becoming a Sith. Thanks to the Rule of Two, there can only be two Sith: master and apprentice. The latter had to prove their loyalty and willingness to give themselves to the dark side, and this was done through a sacrifice (in Anakin Skywalker’s case, for example, he had to choose between Mace Windu and Palpatine, and he ended up facilitating Windu’s death by cutting his hand off). The Sith are an organization with codes and specific practices, and not any dark side user can declare themselves a Sith – in addition to the training, they have to be named a Sith by another one, as its a title.
A dark side user (or dark side adept) is someone with the power to use that side of the Force, and could use many techniques associated to that side, such as force-choking. Dark users and Sith use their hatred and anger to use dark side abilities, which sets them apart from the Jedi. Now, Kylo Ren and Snoke were not Sith, as none of them were trained by one and thus never received such title. Although Snoke was a creation of Palpatine, he wasn’t a Sith, but he was a master of the Force, and was the one who convinced Ben Solo to abandon his Jedi training and turn to the dark side, turning him into his apprentice.
All Sith are dark side users, but not all dark side adepts are Sith, as not all can go through the whole training and be named one by their master. Even though Palpatine was revealed to be alive and Snoke to be his creation, Kylo Ren’s training wasn't that of a Sith, and never got such title from Palpatine, the last Sith alive. Ultimately, Kylo Ren redeemed himself and became one with the Force, and with Palpatine being destroyed for good, there are no more Sith in the galaxy, but there surely are more dark side users.