How is the Decameron organized around 10 narrators and 10 days?

The Decameron, a masterpiece of Italian literature by Giovanni Boccaccio, is structured around a frame story involving 10 young people—seven women and three men—who flee plague-stricken Florence to a villa in Fiesole.1

The organization of the work is as follows:

• The 10 Days: The group spends 10 days telling stories, with the remaining days of their fortnight set aside for religious devotions or personal care.1
• The Narrators: Each of the 10 participants takes a turn as the "ruler" for one day. The ruler of the day sets the specific theme or stipulations for the tales to be told by all members of the party.1
• The Collection: Because each of the 10 participants tells one story per day over the course of 10 days, the work results in a total of 100 tales.1

Each day concludes with a canzone, or song, and the themes range from wit and tragic love to trickery and human will.1