The Eye of Providence, also known as the All-Seeing Eye of God is a symbol that is often used in a religious context. Very often, it is shown as a single human eye, surrounded by rays of light. It is often seen as a symbol for knowledge, or for a god that "sees all". The most common depiction of the Eye of Providence is in the back of the United States one-dollar bill. In a Christian context, it is often inside a triangle, where the triangle represents the Trinity. Freemasons also use the symbol, there it stands for knowledge.