When you search for a room for a date range in Book Now section of QloApps at the back end under Hotel Reservation System Tab and no room is available for any room type but some rooms of same room type or different room types are available on specific dates in that date range so that you can create a booking by combining those rooms for that date range then these rooms are partially available rooms.
Let me explain the concept with the help of an example.
I searched for a room from 1st Jan to 10th of Jan in the Book Now section.
https://prnt.sc/lrzp6l
I found that there is no room available for this date range.
But Room A-102 of General Room type is available from 6th Jan to 10th Jan
https://prnt.sc/lrzrfy
and B-101 of Delux Room type is available from 1st Jan to 5th Jan.
https://prnt.sc/lrzt28
Then instead of turning a guest down, I can offer him these two partially available rooms for the whole date range.
This is the concept of Partial Availability.
And Unavailable rooms are those rooms which are not available at all in the given date range.