I don't think there's any difference when talking about modern day porcelain. But it has a historical difference.
The high firing glazed ceramics porcelain originated in China and for centuries were the sole exporter of it. It wasn't until the early 1700's when Europe figured out how to create porcelain and distinctions are made for collectors of early porcelain work.
Today, most such manufacturing work is no secret and everyone can make them with the same quality produced in factories on assembly lines. So for the average consumer, they don't really mean anything other than maybe the designs on them.
