For nearly 800 years the Catholic Church has utilised the process of the conclave to elect a new pope. “Conclave” means “with a key”, indicating the cardinal-electors are locked up with a key to conduct their deliberations.
With no direct communication to the outside world, a key feature of the papal election process is the use of smoke to signal the result of ballots and to announce the election of a new pope.
Black smoke means a new pope has not been elected. White smoke means there is a new pope.