Read this: Not all traditions of Buddhism share the same philosophical outlook, or treat the same concepts as central. Each tradition, however, does have its own core concepts, and some comparisons can be drawn between them. For example, according to one Buddhist ecumenical organization,[web 23] several concepts common to both major Buddhist branches:

there are common concepts to both major buddhist branches according to what organization?
What is the answer? (If it cannot be answered, return "unanswerable")
Buddhist ecumenical organization