A train ticket and a seat reservation are two different things, although they are related.

A train ticket is a travel document that allows you to board a train for a journey, but does not necessarily guarantee an accommodation (seat/sleeper) assigned to you on board. A reservation guarantees you a specific accommodation on a specific train.

In many cases, train tickets are issued as a combined ticket and reservation: you receive one travel document that indicates the specific train and seat assignment. This is the case for most high speed trains such as Eurostar, Thalys and TGV, as well as for night trains.

In some other cases, you may receive a train ticket and a separate travel document for your reservation. The ticket is then called an 'open ticket' because it is valid on any train running on the route for which the ticket was issued. The reservation portion is a stand-alone document that corresponds to a reserved seat/sleeper that's been booked on a specific train, at a set date and time. The reservation cannot be used by itself. It's only valid for travel in combination with a valid open ticket for the route that the reservation was issued. In general, we'll always issue an open train ticket and a reservation when possible.

By itself, a reservation can NEVER be used to board a train. It must be used in conjunction with an open train ticket, as we've just described, or with a rail pass.