comma before 'and' [serial comma]: Goldberg, Garlin, and Keaton.

[SuperXW]

Hi!
I am studying articles online and find different usages of comma.

From Wikipedia-"Toy Story 3"
"...Whoopi Goldberg, Jeff Garlin, and Michael Keaton."
"...Lots-O'-Huggin' Bear, Big Baby and Ken."

So when writting "A, B, and C" WITH OR WITHOUT a comma are both OK?

 

[entangledbank]

Yes, it's completely optional. There is a tendency for AmE to use the comma more than BrE.

 

[bibliolept]

That last comma, known as the Oxford comma, is not a simple issue. You will find a good discussion here: Comma and And - featuring the Harvard/Oxford comma.

If you have further questions, I encourage you to continue the discussion in that thread.