Trade Free Busy (FB) information itself isn't basic or simple to peruse. This will depict what the information looks like in the Exchange store, how it's computed and prepared through the Outlook customer.
FB depicts when a client is occupied over a scope of time, it doesn't portray every arrangement in that time period. So when you see a client is occupied from 1pm to 3pm, you don't know whether that is one arrangement or a few arrangements. Knowing this will help see how the information is computed and put away. When I say Busy, this could be "Occupied" or "Speculative" or "OOF", they are altogether ascertained similarly.