Train from Berlin to Salzburg

Much less difference than on airplanes. The seat sizes are the same in both classes, but they're spaced farther apart in 1st. For business travelers, you have more work room. There's usually less people. And you get waiter service. That's about it. For most travelers' purposes, 2nd class is more than adequate. Go the Deutsche Bahn website to compare prices.

First class costs about 50% extra, and you get about 50% more space. Seating is 2+1 (seating in second class is 2+2), you get wider seats and proportionally more legroom. Seating in second class is more roomy than most aircraft business classes.

On some 1st class you get a small cold meal or coffee. On German internal ICE trains (Berlin - Salzburg) they bring coffee to your seat But this just saves you getting up to go to the buffet car to get coffee.

In both classes 50% of the seats will be facing backwards. Some seat rows are facing the back of the row in front (like in an aircraft). Some are face-to-face. Then you get a block of 2 seats facing 2 seats with a little table in between, great for families or groups of 4 friends. And in 1st class there are also one-facing-one seat pairs.

And both 1st and 2nd class arrive at your destination at exactly the same time.

If you're planning to book a nonrefundable savings ticket 3 months in advance, then the price difference for the upgrade is very affordable- 39 vs. 29 euros. If you pay full fare, the price difference is significant - 230 vs. 142 euros.