You are referring to the Freemasons. The Eye of Providence (or the all-seeing eye of God) is a symbol showing an eye often surrounded by rays of light or a glory and usually enclosed by a triangle. It is an ancient symbol, and the first all seeing eye can be traced back to the egyptians, as The Eye of Horus.

In recent times this symbol has been associated with freemasonry yes, and it is also the subject of many conspiracy theories etc., my title is mostly tongue-in-cheek.