What is the difference between the Oxford, Harvard, and the Serial comma?

The Oxford comma (also known as Harvard comma or Serial comma) is the comma inserted just before the coordinating conjunction (usually ‘and’ or ‘or’, and sometimes ‘nor’) in the last item of a list of three or more items. For example: Gurpreet's blog is dedicated to Jack, Jill, Red Riding Hood, Captain Kirk, and Spock.

When to use the Oxford Comma?

I use a serial comma ONLY when it satisfies all the following three conditions: