dphil vs phd

A DPhil is the Oxford equivalent of a PhD.
Successfully completing a DPhil usually involves submitting a thesis and then an oral examination of your work, a viva voce . Examiners must be satisfied that your thesis represents a significant and substantial piece of research, is conveyed in a lucid and scholarly manner and that you have a good general knowledge of your academic field.

The University offers research training of a high international standard, with a broad range of subject areas and strong research environments. A doctorate from the University of Oslo qualifies candidates for an academic career as well as other professions requiring a high level of competence.
To be eligible for admission to a PhD programme, certain educational and financial requirements must be met. If you have not applied to a PhD programme before, we recommend that you read this before you proceed to the programme pages.

Refences:

http://www.uio.no/english/research/phd/
http://www.rlf.org.uk/resources/what-is-a-dissertation-how-is-it-different-from-an-essay/