Anomaly/Anomalous — Anything that doesn't follow the rules of reality as we know them.
Object Classes — Each anomaly contained by the Foundation has an assigned object class, which tell you how difficult something is to contain. The three most common classes are Safe, meaning containment is simple, Euclid, meaning containment is more complex, and Keter, meaning containment is very difficult to maintain.
Mobile Task Forces (MTF) — Elite units for responding to and containing anomalies. Depending on the anomaly, these range from paramilitary teams to groups of specialised researchers.
Group of Interest: Groups other than the Foundation that deal with or handle the anomalous.
This is the SCP Foundation Wiki, a collaborative writing site based around the premise that… in essence, magic is real. It's not exactly like the traditional fantasy style magic you've come to know, but that's the best way we can describe the stuff we have here - Anomalies; items and critters that do not follow the rules of nature as we know them. Staircases that go on forever, mechanical gods from the beginning of time, otherwise regular humans who reshape reality with their mind: these are the kinds of things that, if known to the public, could cause mass hysteria and start wars on scales unprecedented. Due to that, there exists an organization called the SCP Foundation, whose job is to research paranormal activity, keep these creatures and objects concealed from the public, and protect humanity from the horrors of the dark.
That's the long and short of it - this site is a place where a bunch of different people write stories about an organization that keeps the inexplicable under lock and key, except instead of just calling it "magic" we use science-y terms like "ontokinesis" or "thaumatology." The wiki started as a horror/creepypasta site so the majority of the older content is focused around that, but since then we've expanded our horizons and nowadays you can find any type of writing you'd want, from novella-length adventures to one-line jokes.