White smoke streamed from a chimney atop the Sistine Chapel, signaling to the world that the 133 cardinals inside have elected a new pope. But we don't yet know his identity.

Here's how the conclave creates black and white smoke and why the Catholic Church began using them to signal whether a new pope has been elected.

At the end of each voting round, black smoke means a new pope has not yet to be selected, while white smoke indicates a new pope has been chosen.