You can access train, metro and bus and even a boat with the same ticket.
You will find 3 kinds of busses in Copenhagen.
- A Bus – runs every 3-7 min (rush hours) and every 10 min (after rush), serve 24/7
- S Bus – runs every 5-10 min (rush hours) and every 20 min (after rush), serve between 6:00 am – 1:00 am
- N Bus (Night Bus) – runs between 1:00 am – 5:00 am
- there is a line called 5C (city line bus), the most busy line in Copenhagen, it goes from the airport, all the way though inner Copenhagen and out to Husum on the other side.
Metro runs 24/7, S-trains runs between 5:00am and 00:30am.
Harbour buses, yellow boats that are part of the public transportation of Copenhagen. The network consist of 3 bus routes (991, 992, 993), with a total of 10 stops along the harbour.
You can buy 24 h ticket for DKK 150, valid in zones 1-99. One adult can bring 2 children under the age of 12, for free on a 24 h ticket. For children under the age of 16, 24h ticket costs DKK 75.
You can buy City Pass that gives you unlimited access to buses, trains, metro and harbor buses in zones 1, 2, 3 and 4, which include the centre of Copenhagen and to and from the airport. An adult 24-hour City Pass costs DKK 80 and an adult 72-hour City Pass costs DKK 200. If you are under 16, a 24-hour City Pass costs DKK 40 and a 72-hour City Pass costs DKK 100.
If you would like to get a bit more, you could get Copenhagen Card. With this one you don't have to worry about tickets and zones, additionaly you get free admission to about 80 museums and attractions in Copenhagen, as well as discounts in some restaurants and cafes. Read more about it here: copenhagencard.com
I recommend to download app called Rejseplanen, it will help you to figure out which line you should use and at which stop you should get off.