Categories for rentable units

Apartment
This is a place with separate sleeping and living areas as well as a cooking area.

Double Bedroom
This is a room for two people with a double bed or two single beds that were put next to each other.

Single Bedroom
This is a room for one person.

Family Room
This room is for three or more people, at least two of the sleeping accommodations are suited for adults.

Holiday Apartment
A holiday apartment is an apartment with a sanitary area and an area for food preparations where guests can stay for a limited amount of time.

Holiday Home
A holiday home is a house with a sanitary area and an area for food preparations where guests can stay for a limited amount of time.

Juniorsuite
A juniorsuite is a room with a separate area for sitting.

Maisonette
A maisonette is an apartment that extends over at least two stories which are internally connected.

Shared Room
This is a room for three or more people.

Penthouse
A penthouse is an apartment that lies in the topmost storey of a multi-storey house and has a large roof terrasse.

Private rooms / lodging
A private lodging is lodging in a private house that have no more than eight beds and are not subject for authorization.

Dormitory Bed
A dormitory bed is in a room with several sleeping accommodations for people that belong to a group (or not).

Studio
This is an accommodation with one room and a cooking area.

Suite
A suite is an accommodation with separate, connected sleeping and living rooms.

Twin Bedroom
This is a room for two people in two separate beds.

Tent
A tent is a portable shelter (usually of canvas stretched over supporting poles and fastened to the ground with ropes and pegs) for one or more people.

Car + Tent
see above with a car

Car + Trailer
A trailer can be connected to a car and can be lived in.

Caravan
This is a car-like motor-vehicle that can be lived in. It is often similar to a trailer.

Source: Deutscher Tourismusverband e.V. (DTV)