What is the difference between first class and second class?

• First class typically has more comfortable, sometimes larger seats, with more legroom than in second class. 
• In some countries, drinks and/or meals may be included in the price, and in others you have the ability to order from the dining car from your seat from first class only. This varies per country. 
• First class is generally less busy than second class. 
• In regional trains, the difference between first and second class may be limited.

For more extensive information, see: Difference between 1st and 2nd class in Europe