What is the difference between first and second class?
First class has bigger seats and more leg room than second class and there are additional facilities in a number of trains. On NSInternational.com you can find an overview of the benefits of travelling first class.
All first class tickets grant access to the NS International Lounge at Amsterdam Centraal, Schiphol Airport and Rotterdam Centraal station.
Facilities in first and second class vary per train. Find an overview of the facilities in your train: