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When you enter Norway, you must present your passport with the visa sticker.
You also have to present documentation that you have enough money to cover your stay, for example cash or a credit card. If you have a financial sponsor, you must bring a copy of the sponsorship form.
The police can also ask to take your fingerprints, which the police will then compare to the fingerprints you registered when you applied for a visa.
As long as your visa is valid, you can travel freely around the Schengen area or the countries for which your visa is valid.
If you travel out of Schengen, for example to the UK, you cannot enter Schengen again. You must then have a visa that is valid for multiple entries or apply for a new visa.