What is the difference between first class and second class?

When booking your Rail Tour, you have the choice between two classes of service: 1st class and 2nd class.

1st class generally offers more spacious seats, more legroom, is less crowded, and depending on the operator may have extra amenities like power outlets and at-your-seat meal services (not included in the price unless otherwise indicated).
Differences between 1st and 2nd class vary across countries and train operators. Regional trains often don't have a large difference between the two classes.
Some regional trains don't offer any 1st class at all. Some tourist mountain railways (Gornergrat, Jungfraujoch) in Switzerland only feature 2nd class, which will be indicated when it is selected as an optional upgrade.

For a more detailed overview of the differences for each type of train in Europe, please see the overview of train types per country (France, Germany, Austria, United Kingdom, Italy, Nightjet sleeper trains).

Pictured: 1st class on ICE trains in Germany

More space: 1st class carriages generally offers wider seats with more legroom, with a more spacious arrangement than in second class. The seats can generally be reclined more than in 2nd class.
Fewer passengers: as seats are arranged more spaciously, 1st class is generally less crowded and has a quieter atmosphere.
Extra amenities: on some trains only 1st class passengers have acces to wifi and power outlets. On some long-distance trains 1st class passengers can be served meals at their seats instead of having to walk to the dining car.
In some countries 1st class passengers might have access to dedicated lounges at the stations or be able to board later (especially on Eurostar trains).

Pictured: 2nd class in an ICE train in Germany

2nd class tickets are typically more budget-friendly, making them a popular choice for travelers looking to save money.
Especially on long-distance trains in Europe 2nd class also offers very comfortable, adjustable seating
On most trains in Europe, there is no difference in luggage allowance between 1st and 2nd class, except on special low-cost high-speed services (like Ouigo trains in France and Spain)
2nd class carriages have more seats, meaning a livelier atmosphere and a greater availability
2nd class passengers also have access to the dining car (if available, although no at-seat service is usually offered) and free wifi