The service between Berlin, Hamburg and Copenhagen is operated mainly by Deutsche Bahn's InterCity Express (ICE) trains, although a couple of services are InterCity trains. There is only one direct service between Berlin and Copenhagen each day in either direction, but plenty of connecting trains available from Hamburg for the final leg to/from Berlin.
The route includes a train-ferry crossing between Rodby and Puttgarden. Passengers are able to leave the train once on-board the ferry to explore a variety of duty free shops, cafes, lounges, bathrooms etc.
InterCity Express:
InterCity Express (ICE) services are high-speed trains linking Germany with a range of other European countries including France, Switzerland, Austria, Belgium and the Netherlands. Services offer both first and standard class accommodation.
Standard class carriages are fully air conditioned, with recliing seats. Seats have fixed or folding tables, as well as luggage lockers. Some special ICE T services allow passengers to sit at the front of the train and take a driver's eye view through a glass partition. First class carriages include power points for mobile phone/laptop charging. Some also feature individual video screens.
ICE trains have a bar/buffet carriage, selling a range of drinks and hot/cold food. There is an at-seat trolley service that travels through both standard and first class carriages.
Passengers are allowed to take two bags/suitcases onboard with them, as well as one piece of hand luggage. Bicycles are also permitted, provided they are in a bicycle bag. Domestic pets may also be transported, with a maximum for two dogs or pet carriers per passenger.