There are more than 60,000 Catholic nuns in the United States, with 750,000 worldwide. As nuns, sisters take three strict vows: chastity, poverty and obedience to God and their church. Nuns believe they are married to Jesus Christ, and some wear wedding rings to symbolize their devotion.
Their traditional clothing is called a habit, which consists of a white cap, veil and long tunic. Nuns consider this their wedding dress.
Not all nuns live the same lifestyle. Cloistered nuns rarely leave the confines of their monastery and pray up to 12 hours a day. Some sisters choose an independent path, which means they live alone, go to college, pursue careers and don't wear a habit.
Oprah Show correspondent Lisa Ling is no stranger to exploring different ways of life. She's traveled to the Congo, reported on North Korea and gone inside a prison. Now, she's going where she's never gone before—inside a convent.