In the advertisement of a living space you can see which facilities belong to the living space. This can be anything, such as the presence of an elevator, whether the living space is furnished, which heating costs you do or do not pay, whether there is a cleaning service, etc.

Unfurnished accommodations usually do not have lamps, bed linen, kitchen utentsils such a pans/pots/cutlery. In same cases the former tenant has furniture to take over. 

Fuily furnished accommodations only require you to bring your suitcase.