Business Rules
Business Rules are the logic that defines what will be done, when it will be done, where it will be done, why it will be done, how it will be done, and how it will all be managed or governed.
Business Rules can take many forms, from simple binary decisions to decisions involving more advanced Boolean logic rules. Examples range from simple yes/no decisions to multi‐threaded decision trees to determine how a process responds to a given event.
Source: Guide to the Business Process Management Body of Knowledge – ABPMP BPM CBOK V3.0.