a comma between the final items in a list, often preceding the word `and' or `or', such as the final comma in the list newspapers, magazines, and books
Let’s Pause And Talk About CommasEverything you want to know about when to use a comma. Learn all the ways to use a comma and the rules for when to use a comma.
Word Origin for Oxford comma
C20: because it was traditionally a feature of the house style at Oxford University Press
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012