Norman and Viking are basically the same thing. The Normans were just Norse who settled in northern France and later invaded Britain and Ireland, while the vikings are Norse who invaded Britain and Ireland directly from Scandinavia. The differences seem to be related to how well the Norse tended to integrate into their new societies, because the Normans had adopted French language and customs in the relatively short time they were in France. This is further illustrated by the phrase that the Normans “became more Irish than the Irish themselves” when they settled here in the 12th century.