Norwegian is a member of the Scandinavian languages, a part of the Germanic branch of language. In Norway there are three official written languages and many spoken dialects. Norwegian (Bokmål, the most often-used variety of Norwegian) is a language spoken by about 5 million people in Norway.
The two official written Norwegian languages are Bokmål and Nynorsk. In addition the indigenous Sámi people have their own official written language. The majority of the people in Norway are using Bokmål. Additionally, Nynorsk is widely used is areas of the Northwestern and southern regions of the country. However, it should be noted that Bokmål and Nynorsk are not classified as two different languages where you have to learn the other as a foreign language; they are more two different written norms. Thus, text written in Bokmål is perfectly understandable for a person using Nynorsk, and vice versa.
Many Norwegians favor their local dialect over the written languages when speaking. For Norwegians the dialect makes up an important part of their identity, and by listening to a person's dialect we can in most cases determine with good accuracy from which part of the country he or she is from. Beginners to the Norwegian language might find some dialects hard to understand, but Norwegians are understanding and speak closer to the written language if they notice you don't understand them. Depending on where you chose to study in Norway, you will come to learn a different dialect and can experience the others while you travel around the country.
If you have a good command of Norwegian you're not only able to communicate with Norwegians, but also with people in Sweden and Denmark. The languages of the three Scandinavian countries are similar and in most cases you can speak in Norwegian to Danes and Swedes, and also read text written in Swedish and Danish. The total population that speak these languages is about 20 million.
But if you’re not planning on learning Norwegian, you should still be able to communicate. Norwegian children start learning English at school at the age of six and thus, almost everyone in Norway has some skill in English (and possibly also German or French).