satanism is to give form to the negative qualities of mankind's mind. That form could be rituals or voodoo or to create an entity (Satan) or entities (devils, demons) that embody only those negative tendencies that all human beings have as potentialities.
I know there are satanists who claim they don't worship Satan, but I believe anyone who uses that word to define who they are is a follower of Satan and evil.
Satanism is a person who faithfully worship Satan, he is their god. Satan bible is the very opposite of the Holy Bible. Its been flip flopped, it says just the opposite.
Satanism is any religion that stems from the Church of Satan, either as a splinter group, or one that kept several ideas from it, while having an ideal that prevented them from feeling comfortable in the CoS [Including Theism, human sacrifice {As is the case with ONA} and others.
I would include the Temple of Set, even though they don't- from my perspective they are just a more mystical CoS, with a more Initiatory body style set up.
Of course, I would say the Church of Satan is also Satanism, obviously.
Part of the issue in defining it, is that it is such a broad topic, with a lot of dissent between the groups- for example the CoS considers, generally, the theistic groups to not be true Satanists.
bunch of delusional non-conformist meeting at 3 in the morning in some abandoned factory to sacrifice hares and do their weird delusional fairytale stuff
where my foundation of the gift i received is now built on giving and helping others, satanic its to gain and feed off of others misfortune and even start this harm itself ! Satan ( legion of the devil ) the evil ones!