If you have a valid Schengen visa, it will be valid in Denmark as well. You will be allowed to travel as a tourist for a period up to 90 days within a 180 days period.
There are three categories of Schengen visa
Short stay visa: This visa allows for single or multiple entries and you can stay in the Schengen territory up to 90 days in the validity period of six months.
Long stay visa: This is issued for a period exceeding 90 days and are issued by the countries. The national legislation rules apply here.
Airport transit visa: This is required for people belonging to certain countries.