Øre is the one-hundredth subdivision of the Norwegian krone, Danish krone, Swedish krona and Icelandic króna currency units. But note that the corresponding subdivision of the Swedish krona is called öre, in the Faroe Islands oyra (plural oyru(r)) and in Iceland eyrir (plural aurar) which are just different spellings of the krone/krona/króna subdivisions. Compare to the cent. The plural and singular are the same in Norway and Denmark.
Since 1993, the only Norwegian coin in use with a nominal value below 1 NOK is the 50 øre coin. (The 10 øre coin was announced deprecated at 23 February 1992 and deemed obsolete one year after that.) See the article about the Norwegian krone for more information.
In Norway and Denmark, the word 'øre' also means 'ear'.