What is single room hotel?

Answer 1

A single room hotel is a hotel room that has one single bed.

A double room hotel is a hotel room that has a double bed.

A twin room hotel is a hotel room that has two single beds.

Do not confuse a "single room hotel" with a "single room occupancy" building...

A single room occupancy (more commonly SRO, sometimes called single resident occupancy is a multiple tenant building that houses one or two people in individual rooms (sometimes two rooms, or two rooms with a bathroom or half bathroom), or to the single room dwelling itself. SRO tenants typically share bathrooms and / or kitchens, while some SRO rooms may include kitchenettes, bathrooms, or half-baths. Although many are former hotels, SROs are primarily rented as a permanent residence.
A set of rooms in a hotel

Answer 2

Usually it has one full sized bed.