on on their power systems division web page has some GER papers that can be found on their web site that does a good job of explaining the difference. Funny, GE was always the 'impulse' turbine co, while Westinghouse has been the 'reaction' turbine manufacturer, and now GE seems to be finding that reaction stages, which infers that there are more of them, might be the way to go. Do you think Thomas Edison still has more to learn from George Westinghouse, and Telsa, since he switched from DC to AC and did it George's way???
There is a lot of technical information if you can find them. I found them via Google.