A physical room is the single accommodation physically present in your structure. Each room must be part of a certain type of room (or room category). The prices of the physical room are defined by the type of which the room is part of.
It coulh happen that a tiny structure (as a Bed&Breakfast) has just one physical room per room type. Anyway, it is good to insert first the room type and then the physical room.
Creating a physical camera is very easy: you have to assign the name and the code (which could also coincide, for example name: 102, code: 102), and type.
The occupancy is the number of adults (and in case children) that the physical rooms can accommodate. At first, the physical room inherits its type occupancy, but it can be changed through the Occupancy field.
A reservation could concern a stay in a single physical room for a certain period of time (arrival, departure), but the same booking could also concern several stays on different physical rooms for different periods of time.
In the example, Janis Joplin reservation concerns two physical rooms 102 and 104 which are part of the same type DBL. The stay on 104 lasts one day longer than the one on 102.
A physical room can be closed for a certain period of time, so the availability on the type is reduced by 1 for that period. In the example the single 101 is closed from 12 to 17 October.