If you have been granted a visitor visa that is only valid for Norway, this will be stated on your visa. This is called a national visitor visa. The reason why you have been granted a national visitor visa is that you have an important reason for visiting Norway, but you do not meet all the requirements for being granted a visa that is valid for the whole Schengen area.
If you have been granted a national visitor visa, you must note the following:
If you leave Norway, you cannot return until you have been granted a new visitor visa.