Does Anyone Know What The SCP Is?

Not too long ago a good friend of mine introduced to me an online organization with some interesting stuff on it, it was the SCP website. Essentially, the SCP website is an online collection of articles addressing strange entities whose safety protocols, descriptions, and supposed "Exploration Logs" are included in each and every article. The articles are categorized by date of completion, and are numbered in the 1-999 and 1000-2000 list. Every item or better known as "SCP" is acknowledged by the preceding acronym "SCP", a hyphen, and then the items' number. In the article, the SCPs specified containment procedure (SCP) is listed under the object class. The object class, or its' safety classification is significantly chosen by the SCPs behavior towards humans. "Safe" means that the SCP will do nothing to harm a human. "Euclid" means that the SCP behavior cannot be predicted, and do not pose any existential threat to humans as the "Keter" class do. "Keter" means that the SCP displays a vigorous threat to human life, and is actively hostile to human life.