The ‘Serial Comma’ , also known as the ‘Oxford comma’ is an optional comma. It is slightly different from the traditional comma in that – it is used before the word ‘and’ at the end of a list. In general, purists do not like comma before the and. Take the following example

We sell fruits, vegetables, and condoms.

The Origin of the word “Oxford Comma” has its history in being used by printers, readers, and editors at Oxford University Press. Not all writers and publishers use it, but it can clarify the meaning of a sentence when the items in a list are not single words:

These items are available in black and white, red and yellow, and blue and green.

The Oxford comma is also known as the ‘serial comma’.

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