What's the difference between a bone marrow needle and a bone marrow biopsy?

Bone marrow fluid smear test is extracted during bone marrow aspiration, and bone marrow biopsy is biopsy after bone marrow tissue treatment. Some diseases (e.g. Leukemia) can be diagnosed by a bone marrow biopsy alone, while some diseases (e.g., MDS, myelofibrosis, etc.) need to be combined with a bone marrow biopsy.