Read: How the Catholic Church chooses its next spiritual leader

When a Pope passes away, many wonder how the next one is chosen.

The requirements are simple: you must be male and a practicing Catholic. However, becoming Pope involves a structured process steeped in tradition.

“You can’t just decide to become Pope,” said a Vatican insider. “It starts with seminary, then priesthood. From there, it’s about earning respect.”

Priests who gain trust in their communities may become bishops. A bishop leads a diocese, which is a specific Catholic district. Some bishops later become archbishops, overseeing multiple dioceses.

Both bishops and archbishops are appointed by the Pope. “These roles aren’t jobs you apply for,” the insider explained. “You need to make a strong impression on the Vatican.”

From the pool of archbishops, the Pope selects cardinals. Cardinals often represent regions with large Catholic populations, but not all areas have one.

When a Pope dies, selecting a new one begins with a conclave. The College of Cardinals under a certain age is called to Rome.

The word conclave means “with a key.” Once it starts, cardinals are sealed inside the Sistine Chapel. “There’s no phone or internet,” one cardinal shared. “Nothing from the outside world can reach us.”

Before voting begins, cardinals attend mass and take an oath of secrecy. They pledge to follow conclave rules.

Voting starts shortly after this ceremony. A cardinal needs at least two-thirds majority to be elected. The cardinals vote up to four times daily until this majority is reached.

Open campaigning is discouraged, but some names are quietly considered. “Your reputation matters,” said one source. “Respect from fellow cardinals goes a long way.”

After each vote, ballots and notes are burned. Smoke from the Sistine Chapel chimney indicates what’s happening.

Black smoke means no Pope yet; white smoke signals that bells will ring. This means a new Pope has been chosen.