In some countries, the purchase of a ticket on a ‘mainline’ or ‘high-speed’ train does not automatically imply a seat reservation.
If you wish to guarantee a seat, you will have to make a separate seat reservation, often at extra cost. So be sure to check your tickets when you buy them. If the seat reservation is already included (and maybe compulsory), the car and seat number will be mentioned.
On regional and tourist trains, there are generally no reserved seats, but beware of peak periods when you may not be guaranteed a seat.
Our advice:
Even if you have a reserved seat, make sure you take it right after the departure so that the train controler can check that the train is full when he first passes. In the event of disruption, the ticket inspector may have to authorise passengers on re-routing to use unoccupied seats. If your seat is occupied, do not hesitate to contact the train controler to resolve the situation.