The Illuminati (plural of Latin illuminatus, "enlightened") is a name given to several groups, both real (historical) and fictitious. Historically the name refers to the Bavarian Illuminati, an Enlightenment-era secret society founded on May 1, 1776. In more modern contexts the name refers to a purported conspiratorial organization which is alleged to mastermind events and control world affairs through governments and corporations to establish a New World Order. In this context the Illuminati are usually represented as a modern version or continuation of the Bavarian Illuminati.

The pyramid
The eye in the triangle above the pyramid
The Roman numerals, MDCCLXXVI, appear on the base of the pyramid and translate to 1776, the year of independence.
Above the "eye" are the Latin words "Annuit Coeptis." This translates to "He has favored our undertakings." This line is associated with the "Eye of Providence."
Below the pyramid are the Latin words "Novus Ordo Seclorum," meaning "A new order of the ages."