Something I just discovered: In train travel, at least in some countries, the classes of service go Second, First, and THEN business. Why is this different from air travel. For that matter, why is business a higher class - I would think business would be geared towards the cheapest prices.

I gather you're referring to China, and perhaps only China. First class and second class seats were well defined long before 高铁 came along, so they needed to call their top class something else.

Not only.

�sterreichische Bundesbahnen a.k.a Austrian federal railway on is RailJet service

http://www.oebb.at/en/leistungen-und...komfortklassen

On DL, FC is domestic only while business class is the top cabin on international flights and nonstop transcons between JFK and LAX/SFO, so business class is better than FC.

I'm not a Delta flyer, so I may be misunderstanding - but I don't think that's an apples-to-apples comparison. The OP and others are referring to when a mode of transportation offers first and business simultaneously - and where business is by definition the higher class of service than first class.

On most legacy USA-based airlines, it's a marketing term to call the front of domestic fights "first class" on 2-class flights. But on flights where there are first, business, and economy classes, "first" always is a higher class of service than "business."

I think the Delta example is relevant, in the sense that business and first are both standardized products.

On Air China's 747-8, the first class cabin is on the lower deck behind business class and before economy class.

Right, but FC is still a higher class of service than business class on CA.

Yes.

Comparing domestic First with international Business is a non-starter. Products have no relation to each other.

On flights with 3 classes of service, First is higher than Business.

On DL, how about business class on JFK-LAX/SFO being higher than FC on ATL-LAX (even on the 777 rather than a 757 or 767), JFK-SAN, JFK-SEA, or LGA-ATL-LAX?

But, IF DL had a three class service, First would likely be above business. Just as it is on say UA.

I am not referring to how each class compares to another one across companies or even within the same company but on different trips. I am talking about on the very same plane/train. In China, and it looks like at least in Austria, if not a few other smaller rail routes, business class is considered more premium than first class. Does this reflect a difference in business practices across countries?

As has been said before, the hierarchy of classes for rail travel has been 1st, 2nd (there also used to be 3rd and I believe, 4th in the U.K.) and has been largely standardised as 1st and 2nd in Europe (post WW-II anyway). So when �BB comes in with a new product, they don't have anywhere to slot it w/o disrupting the hierarchy and since the product is sold all over Europe (not by �BB alone but by at least DB and Hungarian railways) and as interchangeable/connecting fares (with other rail operators), they had to add a new class.

Eurostar also has different classes though I am unfamiliar with how these developed. Runs as Standard (2nd), Standard Premier (1st?) and Business Premier ("Business"). I am not sure if Eurostar sells connecting fares but I do believe they are sold by Eurostar or its subsidiaries only.

As far as fare homogeneity goes, it wasn't that long ago (well, a decade and a half) that some airlines started to introduce premium economy. For a long time, you could not book that class of service even on closely-linked partner airlines (e.g., (not being able to) booking BA PE tickets on AA.com)

You seem to be ingrained with the idea that "first" should equal one thing in context A (flights with 2 classes of service) and a different thing in context B (flights with 3 classes of service).

The Chinese train people have figured out that this system confuses (and, possibly lets down) customers, and so has Delta.

In both cases, expectations are crystal clear:

2nd (CRH), economy (DL) = small
1st (CRH), first (DL) = medium
business (CRH), DeltaOne (DL) = large

The fact that Delta doesn't offer all 3 of these service classes on the same planes is not especially important. Neither is the chosen nomenclature of the service classes.

Amtrak on the Northeast Corridor has, top to bottom,

First - only on Acela Express trains
Business - minimum class on Acela, maximum on Northeast Regionals
Coach - only on Northeast Regionals

Off the NEC i think it's business and coach only, but I could be wrong.

Not strictly relevant, but I managed to irritate a BA employee when I referred to Premium Economy as third class, which, of course, it is.