What are the two selection processes that happen during B cell development?

Positive selection and negative selection are the two selection processes that happen during B cell development. 

During positive selection, the B cell receptor successfully binds its ligand, triggering survival signals. This phase of the selection process ensures that only B cells that have functional receptors will go on to develop further. 

Negative selection always occurs after positive selection. During this phase, B cells that respond to self-antigens in the bone marrow undergo anergy (state of unresponsiveness or functional inactivation), apoptosis (cell death), or receptor editing. This contributes to central tolerance and reduces the risk of autoimmune reactions when the B cells eventually mature and move to peripheral circulation.